2 Existing Status of Irrigation development

2.1    India’s irrigation development: trends and shifts

Recognising the importance of irrigation as a crucial input in India's agricultural development, harnessing of water resources for irrigation has been given an important place in our successive five-year Plans (FYP). The ultimate irrigation potential of the country from major and medium projects is assessed at 58.5 million hectare (Mha). The irrigation potential from minor projects is estimated at 55 Mha, which is undergoing reassessment in view of the possible improvements in water management practices. As against this, the irrigation potential created during the pre-plan period was 22.6 Mha. Further, an estimated 62 Mha of additional irrigation potential has been created during 1951-96 (Table.1). Consequently, up to 1996, 74.5 per cent of the total irrigation potential has been harnessed for expanding irrigation facilities. Major and medium irrigation programmes accounted for 38 per cent of the additional irrigation potential created while the remaining 62 per cent of the added irrigation potential came through minor irrigation programmes. Initially, starting from I FYP, major and medium irrigation programmes contributed around two-third of the additional irrigation potential created (Fig.1). Minor irrigation programmes contributed the remaining one-third. This emphasis was gradually changing and completely reversed from IV FYP onwards extending upto VIII FYP. As a result of this, both surface and ground water resources were harnessed at varying levels across space and time with resultant variations in their multiple impacts, which are highlighted later.

Irrigation development in India accounted for a financial outlay of Rs. 690 billion during I FYP to VIII FYP. The outlay on irrigation includes major, medium and minor irrigation projects and CADA but excludes the flood control programmes. The CADA was initiated in 1974/75 as a Centrally sponsored programme to ensure efficient utilisation of created irrigation potential for optimising agricultural production from irrigated lands. The outlay on minor irrigation projects includes both state and institutional sources but exclude private sources. Within minor irrigation projects, institutional sources accounted for nearly half of the outlay during VIII FYP as compared to negligible level during I FYP. This shift in the funding source (Fig.2) from state to institutional source for supporting minor irrigation programmes started almost from II FYP onwards and stabilised at around 50 per cent from IV FYP onwards with only marginal variations. Such a shift in the funding source for minor irrigation development also provided the fillip for increased share of minor irrigation in the additional irrigation potential created from IV FYP onwards.

Table.1
Progress of irrigation development in India, 1950-96

As percentage of total plan expenditure, outlay on irrigation constituted 23 per cent in I FYP, which came down by almost half in subsequent two plan periods before marginally improving during annual plans and IV and V FYPs. Starting from VI FYP, the share of irrigation outlay has been coming down continuously and has reached six per cent during 1995/96.

2.2    Sources of irrigation development in India: trends and shifts

Changing emphasis on irrigation development per se as well as the sources of irrigation expansion has reflected in differing magnitudes of exploitation of surface and ground water resources over time (Table 2).

Source :    Economic survey, Government of India (Various years) and Centre for Monitoring Indian Economy, Agriculture, November 2000.

Net irrigated area from canal sources has more than doubled to reach 17.1 Mha during 1992/93 from 8.3 Mha in 1950/51. Canal irrigated area is exclusively dominated by government canals. The share of private canals in canal-irrigated area has continuously declined from 13.3 per cent in 1950/51 to only 2.9 per cent in 1992/93. Tank irrigated area has increased during 1950’s and thereafter, continuously declined before stabilising at around 3.1 to 3.3 Mha during 1980’s. Area irrigated by wells showed only a modest increase during 1950’s through mid-1960s before registering impressive expansion during 1966-93 during which the area has more than tripled. There was also a perceptible shift in the sources of area irrigated by wells. During 1951-66, contribution of tube wells remained almost negligible. Starting from 1966 onwards, area irrigated by tubewells increased substantially to reach 15.8 Mha in 1993, contributing 59.6 per cent of the area irrigated by the wells. As on 1993, the total net irrigated area of 50.2 Mha is accounted for by canals (34.1 per cent), by wells (52.9 per cent), by tanks (6.5 per cent) and by others (6.5 per cent). In 1951, the respective share of canals, wells and tanks remained at 39.7, 28.7 and 17.2 per cent of the net irrigated area. The intensive installation of tubewells since 1970s has resulted in wells emerging as the dominating source of irrigation in Indian agriculture. Other sources of irrigation fluctuated around 2.2 to 3.3 Mha accounting for 6 to 14 per cent of the net irrigated area over time.

The growth in source-wise irrigated area exhibited different trends over different time periods in accordance with the shifts in irrigation development policies pursued from time to time. The preceding discussions indicated a perceptible shift in the irrigation development strategies based on which two periods; namely 1951-66 (Period I) and 1971-93 (Period 2) can be broadly grouped for growth analysis (Fig. 3).

The annual compound growth rate for canal-irrigated area came down from 1.8 in Period I to 1.3 in Period 2. Within the Period 2, the growth rate for canal-irrigated area has fallen from 1.7 per cent in 1970s to 0.9 percent in 1980s extending upto early 1990s. While the pace of expansion of canal-irrigated area is almost maintained in 1970s, it has considerably slowed down during 1981-93. The area commanded by tanks has grown at an annual rate of 1.3 per cent during Period 1. But, during the Period 2, the growth rate for tank-irrigated area has become negative at 1.1 per cent. Almost the entire fall in growth rate for tank irrigated area has happened during 1970s with no change in 1980s and beyond. Area irrigated by wells grew at 2.4 per cent during Period 1, which was accelerated to 3.7 per cent during Period 2. Within Period 2, the growth rate of area irrigated by wells was the highest at 4.1 per cent during 1970s, which came down to 3.4 per cent during the later period ending early 1990s.

2.3    Sources of irrigation development in states: trends and shifts

The growth in source-wise net irrigated area also exhibited different temporal and spatial trends as a consequence of shifts in irrigation development policies pursued in the past (Table. 3). As on 1972, excluding the states of minor importance in terms of individual sources of irrigation, the expansion in source-wise irrigated area was analyzed.

*    Figures for 1972 are net irrigated area in thousand hectares for 1971/72.
**    Figures for 1982 and 1993 represent percentage change over 1972 and 1982 respectively.

Among the major states, in case of canal-irrigated area, during 1972-82, the percentage increase was the highest in case of Gujarat (82.8 per cent) followed by Madhya Pradesh (41.6 per cent), Maharashtra (34.4 per cent), Bihar (33.9 per cent) and Orissa (33.1 per cent). Remaining states registered less than one-third increase in canal irrigated area over the 1972 level. Kerala and West Bengal registered decline in canal irrigated area during this period. Marginal decline in canal-irrigated area was also observed in case of Punjab and Tamil Nadu. During 1982-93, canal irrigated area registered impressive expansion in states like Karnataka, Madhya Pradesh, Rajasthan, Maharashtra and Gujarat. All these states registered more than one-third increase in canal-irrigated area in 1993 over the 1982 level. Orissa, West Bengal and Haryana states have recorded 14 to 17 per cent increase in canal-irrigated area during 1982-93 period. Bihar, Tamil Nadu, A.P and Jammu & Kashmir registered decline in canal irrigated area during this period.

Considering both the time periods together, it was observed that states like Gujarat, Haryana, Karnataka, Madhya Pradesh, Maharashtra, Orissa and Rajasthan have consistently increased the area under canal irrigation during 1972-93. In case of Tamil Nadu, the decline in canal irrigated area is consistent although only marginally (3.2 and 5.5 per cent during 1972-82 and 1982-93 respectively). For other states both expansion and contraction in canal-irrigated area was observed during this time period 1972-93.

Among the major states, maximum expansion in tank irrigated area was observed during 1972-82 in case of Maharashtra (32.5 per cent), followed by Andhra Pradesh (28.6 per cent), West Bengal (23.3 per cent) and Orissa (18.2 per cent). Among the states with declining tank-irrigated area during the same period, Haryana and Rajasthan were leading with 52.4 to 54.5 per cent fall, followed by Uttar Pradesh (48.3 per cent), Bihar (30.5 per cent), Kerala (23 per cent) and Tamil Nadu (20 per cent). During 1982-93, Rajasthan registered maximum expansion in tank-irrigated area with 143.5 per cent followed by Haryana (100 per cent), Orissa (44 per cent), Maharashtra (36.5 per cent), Madhya Pradesh (31.1 per cent) and Bihar (28 per cent). Maximum decline in tank irrigated area during 1982-93 was observed in case of Uttar Pradesh (54.8 per cent), followed by Gujarat (35 per cent), Andhra Pradesh (30.2 per cent) and West Bengal (29 .5 per cent).

Across two time periods covering 1972-93, only Maharashtra and Orissa have consistently expanded the area under tank irrigation. On the other hand, Uttar Pradesh, Tamil Nadu, Karnataka and Kerala have registered continuous decline in tank-irrigated area during the same periods. For other states both expansion and contraction in tank-irrigated area was observed during 1972-93.

Well-irrigated area includes the area irrigated by both wells and tubewells. During 1972-82, except Kerala and Gujarat, all other states registered increase in the area irrigated by wells by over 25 per cent. Expansion in well-irrigated area was the highest in West Bengal and Orissa. This was followed by states like Haryana, Bihar, Karnataka, Madhya Pradesh, Rajasthan and Uttar Pradesh accounting for more than 50 per cent expansion in well-irrigated area during this period. Well-irrigated area declined only in case of Kerala and Gujarat during 1972-82. During 1982-93, Orissa and Madhya Pradesh recorded maximum expansion in well-irrigated area. Bihar, Himachal Pradesh, Karnataka, Rajasthan and West Bengal sustained the growth in well-irrigated area during 1982-93 also by registering above 50 per cent growth during this period. While Andhra Pradesh accelerated the well irrigation growth during this period, Tamil Nadu, Haryana, Maharashtra, Punjab and Uttar Pradesh slowed down as compared to the earlier period of 1972-82. Considering both the periods together, impressive and consistent growth of more than 50 per cent in each period is observed in case of several states like; Bihar, Himachal Pradesh, Karnataka, Madhya Pradesh, Orissa, Rajasthan and West Bengal. Barring Jammu and Kashmir with decline in well-irrigated area and Kerala with no change in well-irrigated area, all other states have expanded the area under well irrigation during the later period of 1982-93. Consequently, at all India level also, well-irrigated area has gone up continuously by 52.3 and 42.6 per cent respectively in 1972-82 and 1982-93.

Total irrigated area across the sources has gone up consistently by over 25 per cent during each of the period namely 1972-82 and 1982-93. Only Tamil Nadu has stagnated in providing additional irrigation facilities. Both consistency and improvement in irrigation expansion was observed in case of Karnataka, Madhya Pradesh, Orissa, Rajasthan, and West Bengal. In case of Gujarat and Kerala, total irrigated area declined during 1972-82 but expanded subsequently in 1982-93. In all the remaining states, total irrigated area continued to expand in both the periods but with a declined rate of growth in the later period.

2.4    Shifts in irrigation sources

Varying magnitudes of growth in source-wise irrigated area over time has also resulted in perceptible shifts in the importance of different sources of irrigation over space and time. The state-wise shifts in the sources of net irrigated area during the period 1972-93 are given in Table. 4.

Table. 4
State-wise shifts in sources of irrigated area, 1972-93

Figures refer to state-wise percentage of net irrigated area under each source in respective years.

At all India level, canals dominated the source of irrigation with 41.5 per cent in 1972, closely followed by wells with 38.7 per cent. However in 1982, wells became the dominating source of irrigation with a share of 46.5 per cent, which further increased to 53 per cent in 1993. Consequently, the share of canals in the irrigated area has come down to 34.1 per cent in 1993. Tanks as a source of irrigation also came down from 11.9 to 6.5 percent during the period 1972-93.

Among the states, despite continuous decline in the share of canal irrigated area in the total net irrigated area during this period, canals continued its domination as the major source of irrigation in case of Andhra Pradesh, Haryana, Jammu and Kashmir, Karnataka, Orissa and West Bengal. The share of canal irrigation in the net irrigated area has consistently declined in every state during this period, 1972-93 excepting Gujarat, Himachal Pradesh, Karnataka and Maharashtra.

In case of tanks as a source of irrigation, only Maharashtra has retained its share at around 15 per cent during this period. Every other state has recorded decline in the share of tanks in the net irrigated area during 1972-93. Drastic decline in the tanks' share in irrigated area is observed in Karnataka, Andhra Pradesh and West Bengal.

Orissa and West Bengal registered maximum increase in the share of wells as a source of irrigation during 1972-93. The share in irrigated area by wells has more than doubled in Andhra Pradesh and Bihar. Except in Gujarat and Maharashtra where the wells' share in irrigated area has marginally declined, in most of the other states, this share has continuously increased during this period.

2.5    Farm level irrigation distribution in India: trends and shifts

Distribution of total households and area across different farm sizes for the country as a whole covering five points of time during the period 1970/71 to 1990/91 is given in Table. 5.

Total farm households (FHHs) in India increased from 70.5 million (1970/71) to 106.6 million (1990/91), registering an annual growth rate of over 2.5 per cent. Total farm household area in India however increased only marginally from 162.1 million ha in 1970/71 to 165.5 million ha in 1990/91, recording an annual growth rate of little over 0.1 per cent during this period. Average farm holding size has consequently come down by about one-third from 2.3 ha in 1970-71 to 1.55 ha in 1990/91.

Among different farm sizes, maximum growth in farm households is observed in less than 1 ha size. Number of farm households in this size group has increased by 77.6 per cent during 1970/71 to 1990/91. This was closely followed by 1-2 ha size group whose size has increased by 49.6 per cent. Least expansion was recorded by 2-4 ha size group farms with 30.4 per cent growth during the same period. In case of farm sizes exceeding 4 ha, number of farm households has declined marginally by 4.4 per cent in case of 4-10 ha category and substantially by 40.2 per cent in case of above 10 ha farm size group. Rate of expansion in number of households has consistently exhibited inverse relationship with the farm size across all the time periods considered here. In fact over 3/4th of the increase in the farm households in 1990/91 over 1970/71 has occurred within the 0-1 ha size group. If 1-2 ha size group is also included, then over 95 per cent of the increase in the number of farm households is registered with less than 2 ha size group. Right to land ownership is a necessary condition to acquire right to irrigation water facilities. Therefore, observed shift in the growth of farm households over time, mostly in the range of less than 2 ha size will have different implications on distribution of water and hence income depending on the irrigation water development policies adopted in the past.

Distribution of irrigated farm households across different farm sizes for the country as a whole covering five points of time during the period 1970/71 to 1990/91 is given in Table. 6.

Currently, as on 1990/91, 49.6 million FHH are having wholly or partially irrigated holdings. Irrigated FHH in India has increased by more than two-third during the period 1970/71 to 1990/91. Maximum increase of over 100 per cent is recorded in marginal FHH category and the magnitude of growth in irrigated FHH is inversely related to the farm size. Only in case of more than 10 ha farm size, there is a decline in the number of irrigated FHH by 39.2 per cent during this period. Similar trend is also observed while considering wholly and partially irrigated FHH separately.

The magnitude of growth is more in case of wholly irrigated farms than in partially irrigated farms, which is also desirable from improving the efficiency of use of resources in a wholly irrigated farm environment. However, from equity point of view it remains to be seen whether such an irrigation development path pursued in the past has resulted in more equitable distribution of the irrigation facilities across different farm sizes.

To understand this issue further, percent distribution of irrigated FHH across different farm sizes is provided in Table.7.

For India as a whole, nearly 4/5th of the irrigated FHHs own less than 2 ha of farm holding size in 1990/91. This is higher by 10-percentage point as compared to the distribution of small and marginal holdings in the total irrigated FHHs in 1970/71. Which means in totality, small and marginal holdings account for higher share in the irrigated FHHs now as compared to two decades back. Across the time periods also, there is some consistency in this trend that means the irrigation development policies pursued in the earlier decades did promote distribution of irrigation facilities in favour of small and marginal farms. In all other categories of farm size there is a consistent decline in the percent share of irrigated FHHs.

Among wholly irrigated farms, the percent share of marginal and small FHHs remained more or less constant during this period fluctuating between 69 and 71 per cent and between 15 and 16 per cent respectively. But in case of partially irrigated farms, the share of marginal farms substantially increased from 34.3 per cent in 1970/71 to 48.5 percent in 1990/91. Wholly and partially irrigated farms as a percent of irrigated FHHs is given in Table.8.

Currently, 57.4 per cent of the irrigated farms are wholly irrigated with the rest getting only partial irrigation facilities. This share is 35.7 per cent higher than that of the share realised in 1970/71 level. In the marginal farm holding size, nearly two-third of the irrigated marginal FHH is wholly irrigated with the rest being partially irrigated. This percentage share of wholly irrigated farms in the irrigated marginal FHH category in 1990/91 is 9.3 per cent higher than that of 1970/71. Also in case of irrigated small FHHs, the percentage share of wholly irrigated farms has gone up from 34 percent in 1970/71 to 51.1 percent in 1990/91. Substantial increase in the share of wholly irrigated farms in the irrigated small and marginal FHH categories shows that the irrigation development policies pursued in the past has generated differing impacts across different farm sizes. The inferences are; one, FHH in India has grown annually @ 2.5 per cent; two, irrigated FHH has grown annually @ 3.4 per cent; three, consequently, per cent of irrigated farms in the total FHH has increased from 41.7 per cent in 1970/71 to 46.5 per cent in 1990/91 (Table.9).

Here also, maximum percentage increase in the irrigation coverage during 1971-91 has occurred in the marginal FHHs followed by small FHHs at the aggregate all India level. Further, across farm holding sizes, not much variation is observed in the share of irrigated FHHs in the total FHHs in each size. Irrigated marginal FHH category had the highest share of 47.3 per cent and FHHs with more than 10 ha holding size had the lowest share of 42 per cent. The changes in the absolute and percentage share of irrigated FHHs across farm size at the national level observed during this period indicate a movement towards better equitable distribution of irrigation facilities compared to 1970/71. But, a lot depends on the spatial and source-wise analysis of the equity impacts of irrigation development during the past four decades.

Distribution of net and gross irrigated area by farm sizes for the study period is given in Table. 10.

Net irrigated area has gone up from 29.1 Mha in 1970/71 to 45.7 Mha in 1990/91, registering an annual growth rate of 2.85 per cent. Gross irrigated area increased from 35.7 Mha to 61.7 Mha during the same period, registering an annual growth rate of 3.63 per cent. Since gross irrigated area expanded faster than the net irrigated area during 1971/91, the intensity of irrigated area has gone up by one-tenth during this period.

Expansion in net irrigated area is maximum in marginal FHHs. Annual growth rate during 1971-91 is 5.77 per cent followed by the small farm category which registered 4.58 per cent. Across farm size, expansion in net irrigated area was inversely related to the farm size. Similar trend was also observed in case of gross irrigated area. But in all farm sizes, growth in gross irrigated area is higher than that of net irrigated area. Even here, farm holdings with less than 2 ha size performed better than holdings of higher sizes. For instance, growth in gross irrigated area is 25.9 per cent higher than the growth in net irrigated area. Consequently, intensity of irrigated area has also registered maximum growth in marginal FHHs (13.9 per cent) followed by small FHHs (8 per cent). Only in case of farm holdings with more than 10 ha, net irrigated area declined marginally by 2.6 per cent.

Distribution of surface irrigation facilities that include canal and tank irrigated area across different farm sizes is given in Table. 11.

Table 11
Distribution of surface irrigation facilities by farm size, 1971-91

Canal irrigated area increased by 3.5 Mha during the last four decades. On the other hand, tank irrigated area declined by 5.5 Mha. It is a paradox that while irrigation infrastructure is being expanded through increase in canal irrigation network at a substantial investment, existing irrigation infrastructure in the form of tank irrigation is allowed to shrink. Tank irrigated area has fluctuated during this period especially in the marginal and small FHHs. However, tank irrigation has expanded at an annual rate of 1.38 per cent in the marginal farm category and just by 0.1 per cent in the case of small farm category. In all other farms, with a holding size of more than 2 ha, tank irrigated area has declined and annual rate of decline varied from 0.9 per cent to 3.1 per cent. Despite the limited expansion of tank irrigated area, its role in promoting equity cannot be ignored since share of small and marginal farm holdings in the total farm holdings in the tank command area is very high as of now. Hence, deteriorating tank infrastructure will adversely affect the performance of the tanks and thereby affecting the overall equity of irrigation development. This is more so, since tank irrigation is still an important source of irrigation in several southern states.

For instance, the deteriorating status of tank irrigation infrastructure in Andhra Pradesh is highlighted in Fig.4. Andhra Pradesh has witnessed sharp deterioration in the minor irrigation (MI) infrastructure following the collapse of traditional institutions like kudimaramath that took care of maintenance of thousands of tanks for several centuries. As of to-day, all minor irrigation sources together (consisting of 12351 in number) irrigate

Fig. 4
Deteriorating minor irrigation tank infrastructure in A.P state, 1990s

only, 44.2 per cent of the registered ayacut as against 82 per cent for all the tanks in early 1950s (Table. 12).

Tanks as a source of irrigation in 1960s through 1990s depressed overall annual growth in net irrigated area by about 1/4th in the state of Andhra Pradesh. Neglect of minor irrigation sector's maintenance with major emphasis on major and medium projects has led to continuous deterioration in the performance of minor irrigation (MI) tanks. Total number of minor irrigation sources in A.P is 12351 with a total ayacut of 12.52 lakh ha spread across 23 districts of the state which are grouped under six sub zones under two agro-climatic zones. The tank command area falling under two agroclimatic zones (ACZ 10 and 11) and four sub zones was classified into fully irrigated area, partially irrigated area (stabilization area) and gap ayacut (Fig. 4).

Note:    Figures in parentheses indicate total number of tanks existing under respective categories. MI sources indicate the number of tanks actually in use for irrigation in respective periods. (Source: Season and Crop Report of Andhra Pradesh and Statistical Abstract of Andhra Pradesh, Department of Economics and Statistics, Government of Andhra Pradesh (various years) and Chief Engineer (MI), Minor Irrigation Department, Government of Andhra Pradesh.

The total gap ayacut area in all the 4 sub zones is estimated to be 2.26 lakh ha. This is nearly 5 percent of current net irrigated area from all the sources for the state as a whole. Another 3.30 lakh ha of area currently irrigated by MI Tanks is the area that is partially irrigated during 1990s. This works out to 8 percent of the current net irrigated area from all the sources for the state as a whole. MI tanks located in North coastal sub zone are able to continuously irrigate around 70 percent of the registered ayacut during 1990s. More than 4/5th of the gap ayacut and area for stabilization are located in Rayalseema and Telangana regions of AP

Out of 12351 MI sources, 30% is located in eight drought prone districts viz.; Prakasam, Chittoor, Cuddapah, Anantapur, Kurnool, Nalgonda, Mahaboobnagar, Rangareddy and 26 % of the Ayacut area under MI sources is located in these districts. As per Central Ground Water Board (Southern region), Ministry of Water resources assessment, more than 4/5th of the mandals identified under grey and dark categories are located in the Rayalseema and Telengana regions. Furthermore, tanks irrigate 29% of net irrigated area, presently cultivated by marginal farm holdings. 54% of the net area irrigated by all tanks in the state is distributed between marginal and small farm holdings. In terms of number of farm holdings, 80% of the farms receiving tank irrigation are small and marginal farms (less than 2 ha in size) in Andhra Pradesh state. Marginal farms (less than 1 ha in size) alone constitute 60% of all the farms getting irrigated by tanks. Farms that are less than 0.5 ha in size constitute 40% of all the farms receiving irrigation water from tanks in the state. This implies that deteriorating performance of the tanks in the state will have unfavourable distribution impacts between regions as well as between various farm size groups within the region. The infrastructure status of MI tanks in the state of A.P as exists today demand appropriate intervention to restore its potential functioning in meeting the multiple needs of the village society. In the neighbouring state of Tamil Nadu also, the area irrigated by tanks has come down from 9.36 lakh ha in 1960/61 to 6.74 lakh ha in 1994/95. As percentage of net irrigated area, the tanks' share has declined from 38% in 1960/61 to 23% in 1994/95 (DoA, Tamil Nadu, 1997).

Distribution of well and tubewell irrigated area across the farm sizes in India during 1971/91 is given in Table.13.

Well-irrigated area has gone up from 6.7 Mha to 9.1 Mha during this period registering an annual growth rate of 1.81 per cent. Tubewell irrigated area recorded an increase of around 10 Mha with an annual average growth rate of over 10 per cent. Relative to tubewell irrigated area expansion, well irrigated area remained more or less stagnant during this period. Among all farm holdings, least annual growth of around one per cent was observed in the marginal farm holdings obviously because of unviable farm size to make capital investment in wells. Large holdings of more than 10 ha registered marginal decline in the area irrigated by wells during the same period.

Over time, informal institutional sharing of wells by more number of marginal farm holdings also came under social stress resulting in limited growth in well-irrigated area under this category. Declining ground water table also contributed to the failure of wells totally or partially restricting the per well command area in states like Karnataka. Initial failure and falling life of irrigation wells has become a common feature in hard rock regions. For example, in eastern dry zone of Karnataka, the (negative binomial) probability of well failure is estimated to be 40 per cent (Nagaraj et al.,1994). Maximum growth in well-irrigated area has been recorded in the farm holding sizes ranging from 1 to 4 ha in which annual average growth rate varied from 2.92 to 3.26 per cent during 1971/91.

In case of tubewell-irrigated area, expansion is phenomenal in the marginal FHHs followed by small FHHs. The magnitude of expansion in tube well-irrigated area is inversely related to the farm holding size. With a skewed distribution of farms in favour of marginal and small holdings, faster expansion in tubewell irrigation in the marginal and small holding categories tend to promote overall equity in the distribution irrigation facilities.

Annual average growth in tubewell-irrigated area is maximum at 19.4 per cent in marginal FHH followed by 15.3 per cent in small FHH. In both categories, recorded growth is much higher than the over all growth of 10.16 per cent observed across farm sizes during the period 1971/91. In other words, growth in farm holdings less than 2 ha was the driving force behind the over all expansion in the tubewell irrigated area during the past four decades. Innovative pumping technology matched by electricity expansion and coverage in the farm sector made ground water pumping scale neutral providing assured irrigation coverage and thereby, complementing the adoption of seed cum fertilizer led modern technology.

The percentage distribution of farm households, total area, irrigated area and source-wise irrigated area during 1970/71 to 1990/91 by different farm sizes is given in Table.14. The share of marginal FHH in the total FHH has increased from 51 per cent to 59 per cent during the past four decades. Both marginal and small FHHs alone account for 78 per cent of the total FHHs in the country as of 1990/91 cultivating nearly one-third of the total area. This has implications for the equitable distribution of irrigation impacts from the past irrigation water development strategies.

Collectively, small and marginal farmers are now operating 32 per cent of the total area as against 21 per cent of the total area operated by them four decades back. But the share of small and marginal FHH in the total FHH has gone up from 70 percent in 1971 to 78 percent in 1991. Since providing irrigation water is expected to have a catalytic impact on farm income and hence alleviation of rural poverty, spreading irrigation coverage in proportion to the share of FHHs in different size groups is useful to promote the equity impacts of irrigation development in India.

In terms of the distribution of net and gross irrigated area among the farm sizes, it is seen that the share of farm holdings with less than 2 ha has improved from 31per cent in 1970/71 to 41 percent in 1990/91. In 1970/71, the share of small and marginal holdings together in the canal irrigation source is 31 per cent. By 1990/91, this share of canal irrigation source in holdings with less than 2 ha went up to 41 per cent. Similarly, small and marginal holdings accounted for 40 per cent of tank irrigated area in 1970/71, which went up to 55 per cent in 1990/91. While tank irrigated area itself is declining due to the neglect of this important traditional infrastructure, its increased importance for the small and marginal holdings underlines its continued importance in improving the equitable distribution of irrigation benefits in favour of farm households with less than 2 ha.

Distribution of well-irrigated area highlights its dominance in the holdings with 1 to 10 ha size and stagnancy in its expansion or even decline in its percentage share in case of other farm sizes. In 1970/71, the share of FHH with less than 2 ha size accounted for 29 per cent of total tubewell irrigated area. But in 1990/91, this share of small and marginal FHH in total tubewell irrigated area has increased to 44 per cent underlying the scale neutrality of this technology, the adoption of which was necessitated by the spread of modern varieties during the green revolution period.

Analysis of percentage distribution of FHHs and area across different farm sizes revealed the following: One, FHHs are predominantly distributed in the smallest holding size category of less than 1 ha and this trend will continue. Two, such a distribution will tend to sharpen more the equity related issues particularly in irrigation water, which are invariably, linked with the ownership rights of the land. Three, distribution of canal, tank and tubewell irrigated area has changed following the irrigation development strategies pursued in the past four decades. Four, the observed change in the source-wise distribution of irrigation benefits indicate a shift towards small and marginal FHHs whose share in canal, tank and tubewell irrigated area at aggregate national level has improved during the period 1971-91. However, only empirical analysis of the equity impacts of irrigation development by sources and regions over different time periods will help in the assessment of current status and needed future strategies.

The distribution of area under rice, wheat and cereal group as a whole is presented in Table. 15.

Total area under rice increased by about 1.26 per cent per annum while, wheat area expanded by 3.29 percent per annum during the period 1976-91. Area under cereal crops as a whole increased by around half a percent per annum. Rice and wheat area expansion provides differing patterns. Maximum rice area expansion occurred in the marginal farm households with an annual growth of 3.3 per cent followed by small farm household category with an annual growth of 1.9 per cent. Farm households with a holding size of 2-4 ha recorded little over 1 per cent expansion in rice area while more than 4 ha holding size categories registered decline in both absolute and percentage rice area during 1970/71 to 1990/91.

Wheat area expanded in all farm-holding sizes. In small and marginal FHHs, the rate of expansion in wheat area is highest and almost same. Wheat area expanded in farms with holding size of 2-4 ha and 4-10 ha at 32.4 to 52 per cent during this period. Cereals as a group registered expansion in area in case of farms with holding size up to 4 ha but declined by over 1.6 per cent annually in farms with holding size more than 4 ha during the period 1977-91. The distribution of irrigated area under rice, wheat and cereals by farm size is given in Table. 16.

Total rice irrigated area registered an average annual growth rate of 2.73 per cent during 1971/91. Expansion in wheat-irrigated area during the same period was at an annual average rate of 4.55 per cent. Irrigated area under cereals as a group itself has expanded at an impressive rate of 3.14 per cent per annum during the past four decades ending 1990/91. Among different farm sizes, the rate of expansion in the irrigated area under rice, wheat and cereals showed inverse relationship with the farm size. Marginal farm holdings recorded 5.94 per cent growth in the irrigated rice area per annum followed by small farm holdings with an annual average growth rate of 3.93 per cent. The irrigated area under rice registered a decline of about half a percent, only in case of holdings with more than 10 ha.

Wheat irrigated area almost trebled during the period 1971/91 registering an average annual growth rate of 9.7 per cent in case of marginal farm holdings. In holding sizes of 1-4 ha, irrigated area under wheat either doubled or more than doubled during this period. Unlike in case of rice, wheat area expanded in case of all the remaining farm sizes also.

The crop-wise irrigated area distribution under cereals by farm size revealed the following: One, with increased irrigation coverage for marginal and small farm holdings, the share of irrigated area allocation for wheat followed by rice has increased substantially during the past four decades ending 1991. Two, more equitable distribution of irrigation benefits is expected to bring in more irrigated area under cereal crops particularly wheat and rice. Three, promoting equity in irrigation development over space and farm size will diversify the present narrow production base of cereal crops like rice and wheat.

The distribution of area under food grains, food crops and non-food crops is presented in Table. 17.

Area under foodgrains increased at an annual rate of 0.84 per cent. Area under food crops registered an annual average growth of 0.96 per cent during 1977-91. Non-food crops showed an impressive growth of 3.34 per cent per year during this period. Since rice and wheat area dominated the area under food grains, the growth rates observed in case of foodgrains in almost all farm sizes exhibited more or less similar trends as observed in case of rice and wheat area. Similarly, food grains being the dominating group within the food crops area, the trends in growth rate registered across different farm sizes remained almost similar to that of food grains. Noticeable decline in area under food grains as well as food crops was observed only in case of more than 10 ha category. Farms with 4-10 ha holding size registered marginal decline in the area under food grain and food crops during this period. In case of non-food crops, area expansion was maximum in marginal as well as small farm holdings with an annual average growth rate of around 9 per cent. This growth rate is much higher than that of other farm sizes excepting those with more than 10 ha, which recorded marginal decline in the area under non-food crops. The distribution of irrigated area under food grain, food and non-food crops by farm size is given in Table. 18.

The area under food grain and food crops expanded, individually, by almost same magnitude of around 3.2 per cent per annum during 1971/91. However, the rate of expansion in non-food crops is almost double than that of food grain and food crops during the same period.

Irrigated area under food grains as well as food crops more than doubled in the marginal FHHs, registering an annual average growth rate of around 6.5 to 7 per cent. The irrigated area expansion in other farm sizes up to 10 ha is less than that of marginal farms but still impressive. The irrigated area expansion under food grain and food crops in case of farms with holding size more than 10 ha is either negligible or marginally negative. In case of non-food crops, the irrigated area expansion is impressive at an annual average rate of 8.3 to 10.92 per cent in farms with holding size up to 4 ha.

Analysis of area under food and non-food crops across farm holdings and different time periods revealed the following: One, rate of expansion in area under food grain and food crops is inversely related to the farm size. Two, this expansion is limited to farms with holdings less than 4 ha. Three, despite the small share of non-food crops in the total area, the area under non-food crops has expanded in all size groups impressively except in more than 10 ha farms. Four, almost similar trends but larger in magnitude are observed in the expansion of irrigated area under food grain, food and non-food crops across all farm sizes. Finally, distribution of irrigation benefits exhibited differing impacts on the distribution of crop and crop group wise irrigated area under cereals, food grain, and food and non-food crops.

The distribution of crop area by farm size expressed as a percent of total crop wise area under each farm size is given in Table 19. In 1976/77, 27 per cent of the gross cropped area was operated by farm holdings with less than 2 ha size. This share went up to 35 per cent in 1990/91. In case of rice, 42 per cent of the total rice area in 1976/77 is cultivated by farm holdings with less than 2 ha which increased further to 49 per cent in 1990/91.

Similarly, share of wheat area in small and marginal holdings increased from 33 to 39 per cent in this period. Cereals as a group in these holdings of less than 2 ha also increased their share from 31 to 42 per cent during 1977-91.

Share of food as well as non-food crops also increased by 31 to 53 per cent in 1990/91 over that of 1976/77. It is thus observed that, with increase in gross cropped area, increased share of area under rice, wheat, food and non-food crops are recorded in small and marginal farm households.

The distribution of irrigated crop area by farm size is given in Table 20. Overall share of total irrigated area (GIA) increased by 35.5 per cent during the period 1971-91 in case of holdings less than 2 ha. This share, in case of bigger holdings with more than 2 ha, declined by 14.5 per cent during the same period. Percentage of irrigated area under rice and wheat respectively operated under less than 2 ha holding size improved by 29 and 38 per cent during the past four decades. Share of wheat and rice irrigated area remained same in the 2-4 ha holding size group but declined by 22.9 to 29.7 per cent respectively during the past covering 1971-91. Irrigated area under cereal crops in farm holdings with less than 2 ha occupied 45 per cent of the irrigated area under cereals in 1990/91, which is 36.4 per cent higher than that of 1970/71.

The share in respect of foodgrains and food was 43 and 44 per cent respectively, which is higher by around one-third as compared to their share in 1970/71. The analysis of irrigated crop area distribution across farm sizes in the past four decades reveals the following: One, additional gross irrigated area generated during the past four decades got distributed more in favour of small and marginal FHHs. Two, irrigated area share of rice and wheat in the small and marginal holdings has increased but declined in case of holdings with more than 4 ha. Three, since rice and wheat are the dominant crops in cereals, food grain and food crop groups, similar trend was observed in the share of irrigated area allocation under cereals, food grain and food crop groups.

The distribution of irrigated crop area expressed as a percent share of total crop area by farm size is given in Table 21.

Irrigated area share in the gross cropped area has increased from 34 per cent to 43 per cent in case of marginal farm holdings and 30 to 37 per cent in case of small farm holdings during this period namely 1976/77 to 1990/91. Percent of gross cropped area irrigated in different farm sizes varied inversely with the farm size and this inverse relationship was maintained in all the decades ending 1990/91. The impact of irrigation development on the percentage share of gross cropped area irrigated varied with farm size even though the inverse relationship as observed above remained intact during the period covered in this study.

Across farm sizes, percentage share of irrigated area in the gross cropped area has expanded at an annual growth rate of around 3 per cent during 1977-91. Irrigated area under rice grown under irrigation increased its share from 36 percent in 1977 to 46 percent in 1991. Share of irrigated area under wheat improved substantially from 63 per cent to 79 per cent during this period. The percentage share of cereals, FG, food and non-food crops cultivated under irrigated situation got more than doubled during the same period.

Among different farm sizes, increasing trend in the share of irrigated area in each of the major crop and crop group considered here is observed in all the FHH categories. Notably, share of wheat irrigated area increased substantially in the farms with holding size above 10 ha. Share of irrigated area under non-food crops also nearly doubled for all the farm sizes with impressive increase in the share observed in all the FHH categories.

Distribution of crop area expressed as a percent of gross cropped area for each farm size is given in Table 22. Share of rice area in the total GCA remained almost same during the period 1977-91 but wheat area share improved from 11 to 14 per cent during this period. Area share of cereals, foodgrains and food crops declined but non-food crop area share in the gross cropped area increased by 27.8 per cent during the same period.

Between farm sizes, rice area share in 1990/91 accounted for 37 per cent of gross cropped area in marginal farms, which recorded marginal fluctuations during 1977-91. Share of wheat area in gross cropped area increased by one-third to reach 16 per cent in 1990/91 from 12 per cent in 1970/71. Both wheat and rice occupied little over half of the gross cropped area in the marginal FHH category. Percentage share of rice and wheat in the gross cropped area of respective farm size groups exhibited inverse relationship with farm size. Largest farms with more than 10 ha holding size allocated 24 per cent of gross cropped area for rice and wheat.

Share of non-food crop in the gross cropped area improved marginally in the holding sizes of less than 2 ha and substantially in holding sizes with more than 2 ha. Share of cereals, foodgrains and food declined with differing magnitudes in different farm sizes during the period 1977-91.

As of now, more than 4/5th of the gross cropped area is allocated for food crops in the marginal FHHs. In the largest FHHs, little over two-third of the gross cropped area is allocated for food crops. This is again inversely related with the farm size. Share of cereals in gross cropped area is now little over two-third and food grain crop share in gross cropped area is little over three-fourth in the marginal holdings. With increase in farm size, these shares have come down to half of gross cropped area getting allocated for cereals and little less than two-third of gross cropped area getting allocated for food grain crops in the farms with more than 10 ha holding size. The percentage allocation of gross cropped area for food and non-food crops individually for major crops and crop groups revealed marginal decline in the share of rice, cereals, food grains and food and marginal increase in wheat and non-food crops.

Distribution of irrigated crop area expressed as a per cent of gross irrigated area in each farm size category is given in Table 23.