The Indian hot arid zone occupies over 31.7 m ha area of which 81.0% lies in two states i.e. Rajasthan and Gujarat. The characteristic features of this region are low and erratic rainfall (100 -420 mm/year), extreme temperatures (-5.7 to 50.0°C), long sunshine duration (6.6-10 hours), low relative humidity (30%-80%) high wind velocity (9-13 kmph) and high evapotranspiration (1500-2000 mm). The soils are poor in nutrients, wind erosion occurs on a mammoth scale and paucity of water is a perennial bottleneck.Dryland farming in farming system mode is the main occupation of the people . With limited and degrading resource base and climatic vagaries, arable cropping has now become more risky and vulnerable. The crop yields are meager and unstable and consequently the income from the existing cropping alone is hardly sufficient to sustain the farm family. To minimize the risk and uncertainty, farmers in this region practice farming systems in one form or other. In fact traditional farming systems represent a crop –livestock- tree/shrubs – human continuum. The local inhabitants have evolved suitable land use and management systems of farming, pastoralism and animal husbandry. However, these local survival systems have now become inadequate to fulfill the needs of ever increasing population. Over the years, economic considerations have overtaken the sustainability issues. This has resulted in over-exploitation of the resources causing rapid and widespread land degradation and decline in productivity. Integrated farming system (IFS) approach has been widely advocated as a means to harmonize use of scarce inputs so as to make the production system sustainable and climate smart. IFS besides increasing system productivity also envisages harnessing complementarities and synergies among different agricultural sub systems/ enterprises and augmenting the total productivity, profitability, sustainability and gainful employment for a house hold.The different components of IFS are described here.
Alternate Land use systems
To mitigate the risk and uncertainty of income, it is essential to integrate various agricultural enterprises in production programme that yield regular and evenly distributed income, cater diverse needs of farmers’ family along with imparting sustainability through conservation and improvement of natural resources in fragile arid ecosystem. These regions are endowed with appreciable agro-ecological diversity and hence various components viz. crop, animals, tree, grass, fruit tree, can be integrated in production system. Choice of these components is dictated by interaction of edapho-climatic, technological, infrastructural, institutional, household, policy and socioeconomic factors. The areas falling in <250 mm rainfall zone have predominance of grasses and shrubs; hence range/pasture development with livestock rearing is the major proposition. In areas receiving rainfall between 250-350 mm besides grasses and shrubs, multipurpose tree species dominate and mixed farming encompassing agroforestry system, mixed cropping, livestock and pasture management are main livelihood options. In areas receiving rainfall >300 mm crops and cropping system diversification, agroforestry and livestock rearing are major systems of sustenance of arid zone farmers. About 60-70% of farmers in this region resides in village and cultivates their lands only in rainy season. The rest 30-40% farmers made their dwellings on their farms and thus have better control over and management of their land and vegetation resources. Absentee landlords are another lot having large holdings and leasing out lands for cultivation. Appropriate farming systems could be different for these situations, cropping systems and diversification of crops for first category, integrated farming system with emphasis on perennial component for second category and capital intensive systems like agro tourism may suit last category . Hence, crop and enterprise diversification are the drivers of any strategy made for combating uncertainties in arid regions.
Diversification of crops and cropping systems with the aim of increasing resource use efficiency and profit seems to be a viable option to impart resilience in agricultural production system. The intercropping of compatible crops is time tested strategy for improving productivity, resource conservation and reducing risk in arid region. Intercropping of castor + Sesamum(1:3) and castor+ groundnut(1:3) was found more remunerative than sole cultivation of respective crops in Kachchh region of Gujarat. Moth bean - clusterbean cropping systems is better in term of productivity, return and water use efficiency in dune soils .Diversification of traditional cotton-wheat cropping system with low water requirement crops e.g. green gram, castor+ lobia in rainy season and barley, mustard and gramin winter season was found more remunerative and water efficient .Diversification of arable cropping through inclusion of more efficient, competitive and high value- low volume commodities like medicinal, dye yielding crops is also an important strategy to overcome many constraints faced by the farmers in arid region. This includes Cassia angustifolia, Aloe vera, Plantago ovate and Lawsonia (henna). Cultivation of Aloe in strip plantation also arrested soil erosion .
Growing of trees with agricultural crops is an age old practice in arid and semi-arid region of India. Trees by virtue of their perennial nature impart stability in production along with improvement in microclimate and soil fertility. Prosopis cineraria (Khejri) and Ziziphus nummularia (Bordi) are the two most important multipurpose woody components intraditional agro-forestry system of the region. Besides good yield of dry land crops, bonus yield of dry leaves and twigs ( 650-1050 kg ha-1) and fuel wood (1.8-2.6 t ha-1) could be obtained from Prosopis tree through annual lopping . A tree density of 100-200 plants ha-1 was found optimum for minimum interference with yield of dry land crop like clusterbean under P. cineraria canopy shade. Vigna sinensis and pearlmillet showed better performance with tree species than Vigna radiata and Vigna aconitifolia. Studies conducted at Pali revealed that strip cropping of mehndi consisting 4 rows of henna alternated with 4 rows of clusterbean at 60 cm spacing provided higher return than their sole planting. Tecomella undulata, Hardwickia binnata and Holoptelea integrifolia are the other important tree components. Besides improving productivity, the agri-silviculture system improves the soil properties.
Cropping between grass strips laid out against prevalent wind direction not only reduce soil erosion but also provide at least some biomass during low rainfall years. In good rainfall year, production of arable crops increase along with increased forage yield of grasses. A strip cropping of grasses and kharif legumes in 1:2 ratio has been recommended, with a strip width of 5 m. Ley farming also increased grain yield of crop significantly over control. Intercropping of arid legumes with Cenchrus ciliaris gave higher yield, return and moisture use efficiency than sole pasture.
It has been found to be best suited for areas receiving <200 mm rainfall, or in degraded rocky-gravelly areas. The highly compatible trees with grasses are: Acacia senegal, A. tortilis, Albizzialebbek, Tecomella undulata, Colophospermum mopane, Dychrostasis nutans,Hardwickia binnata, Z. nummularia and Z. rotundifolia. Among the pasturelegumes Clitoria ternatea and Lablab purpureus showed good compatibilitywith L. sindicus and C. ciliaris. Production from a silvipastoral system withA. tortilis and C. ciliaris was higher than that from a pure pasture . The carrying capacity of a pure pasture was found to be 3.9sheep ha-1 after 9 years of establishment, while that from a silvi-pastoral system was 8.5 sheep after 7 years. Under goat grazing, Z. nummularia with grass strips in 1:2 ratio led to higher economic returns due to weight gain of the animals and higher wool production.
Horticulture based production system is considered effective strategy for improving productivity, employment opportunities, economic condition and nutritional security. Several drought hardy fruit crops like Cappirs decidua, Salvadora oleoides, Cordia dichotoma, Cordia gharaf, Zizyphus nummularia var. rotundifolia, Z. mauritiana are suitable for the area receiving rainfall <300 mm. Besides providing fruit these plant produce moisture laded nutritious leaves for animal. Several other fruit such as aonla, pomegranate, bael ( Aegle marmelos), datepalm, imli (Tamarindus indica) can be grown in the area having irrigation facilities. Among the vegetable crops Solanum melongena, Lagnaeria siceraria, Luffa acutangula, Luffa cylindrica, Citrullus lanatus, C. lanatus var. fistulosus, Cucumis melo var. utillismus, C. melo var momardica, C. callosus, Moringa oleifera, Cymopsis tetragnoloba and Vigna ungiculata are suitable for horticultural based framing systems.The management practices of horticultural crops have been standardized for optimizing the productivity. Water harvesting techniques has developed to augment water availability to fruit plants. Circular catchmentsaround each tree (1.5 m radius) with 5% slope towards tree trunk and covering the catchment with black polyethylene sheet has found effective to conserve moisture. Agri-horti system comprising Zizyphus + mungbean provided fruit, fuel wood and round year employment even in below average rainfall year . This system is recommended for the region having rainfall <250-300 mm. Intercropping of bottle guard and during kharif season and pea (arkel) andkasuri methi with ber plantation did not cause adverse effect on three yearold ber .Pomegranate has been found compatible with pearl millet, mung bean,Isabgol, sorghum and cumin in jalore district of Rajasthan.During juvenile phase of fruit tree, there are ample opportunities for raising annual, biennial and perennial crops which can meet diversified need of farmers.
Integrated Farming system Models for Arid Zone
On the above considerations and keeping in view the large size of holdings in desert areas, a 7 ha Integrated farming system model has been developed based on twin strategy of system as well as crop diversification. This includes arable cropping (15%), agroforestry (35%), agri-horticulture (20%), agripasture (10%) and silvipasture (20%). Crop diversification of pearl millet (40%) with pulses (30%), oilseed (10%) and clusterbean (20%) was found more profitable and sustainable.The perennial components are Prosopis cineraria, Hardwickia binnata and Acacia tortilis in agroforestry, Zizyphus mauritiana in agri- horticulture, C. mopane and Z. rotundifolia in silvipasture. Ten years of study of this model indicate that amongst farming system components. B:C ratio was highest in the silvipasture (3.11) and was the lowest in arable farming (1.62). The system as per family and herd size was surplus in pulses, fruits, fuel-wood and milk whereas; it was marginally deficient in cereals, fodder & concentrate but substantially deficient in oilseeds. Hence the diversification of FSC should be in tandem with growing family needs and natural resource sustainability. Over the decade (2001-10) the IFS model had showed reasonable IRR (21.6), NPW (US$ 10560) and B:C ratio (2.05). Besides, a huge amount of carbon sequestered in tree components and into the soil. This system has shown resilience in low rainfall years (2004, 2009), long dry spells of midterm drought (year 2008, 2011), delayed onset of monsoon (2006, 2012) besides recurring terminal droughts. In all such situations, the perennial component like, fruit, fuel wood and fodder trees as well as perennial grasses provided the much needed cash as well as fodder for sustenance of livestock.
S.P.S Tanwar1, Suresh Kumar2 & M.M. Roy3
1 Senior Scientist, 2 Head, Division of Integrated Land Use Management & Farming Systems, 3Director,
Central Arid Zone Research Institute, Jodhpur 342 003