for dryland area
Dry farming or dry land farming is the practice of crop production entirely with rain-water received during the crop season or on conserved soil moisture in low rainfall areas of arid and semi-arid climates and the crop may face mild to very severe moisture stress during their life cycle. Dry land farming is characterized by having:
Soil types in dryland areas
Five types of soils observed are black, alluvial, red (laterite and lateritic), sierozems and submontane soils. In the north and northwest of the country, alluvial, sierozemic and submontane soils predominate. In central and south India, black and red soils occupy the highest area. In the higher rainfall regions and coastal areas, the laterites and lateritic soils predominate.
The black soils are deeper, clay to clay loam and characterised by low permeability and high water holding capacity. Low infiltration rate, high plasticity and stickiness, low organic matter content, high CEC, the calcareous nature and slightly alkaline reaction, pose problems of management practices, Vertisoils, when kept fallow during Kharif, are exposed to soil erosion hazards.
The red soils are light textured, shallow to medium in depth and usually underlain by compact subsoil, fairly porous and low water holding capacity. Soils are prone to erosion and surface crusting. Because of crust formation run off Alfisols is more than in Vertisols. Crusting just after seeding results in the poor emergence of seedlings, particularly in the case of small seeded crops such as finger millet and pearl millet.
These soils are fairly level, deep, light to medium in texture with favourable physical characteristics and good permeability. Small showers are useful and there is the utilisation of most of the water held by the soil due to low moisture content at wilting point.
Very deep alluvial sandy loams, low soil moisture storage, instability of soil structure, and poor soil fertility is the major problems of soil management in the desert ecosystem. High wind velocity leads to servere wind erosion. Soil drifting leads to soil and nutrient losses. Surface crust formation after sowing following light showers limits the desirable crop stand. These soils are observed in Dantiwada, Hisser and Jodhpur.
Such soils are distributed in the dry subhumid environment of Hosiarpur in Punjab and Rakh Dhiansar in Jammu and Kashmir and in the humid tract of Dehradun. The lands are sloping, the soils range from loamy sands to sandy loams, silty loams and clay loams with soil moisture storage capacity improving in that order. Soil crusting occur in soils of dry and sub-humid regions.
Edaphic Problems associated with dryland farm.
Reduction of moisture loss due to Evaporation and Transpiration
Following measures are taken to reduce the loss of moisture received by the soil.
Cropping systems differ according to climate and soil types. The areas with 400 to 750 mm annual rainfall, mono cropping with traditional long duration crops is common. Generally adaptable crops are cercals, oil-seeds, pulses.
When the rainfall is between 500 to 700 mm with a distinct period of moisture surplus, the intercropping system can be adopted. Intercropping facilitates the growing of either cereal + legume or legume + legume. e.g. are: sorghum + pigeonpea, pearl millet + pigeonpea, sorghum + green gram, sorghum + soybean, groundnut + pigeonpea and foxtail millet + pigeonpea.
In areas with more than 750 mm annual rainfall with a soil storage capacity of 150 mm or more of available moisture sequential cropping is possible. e.g. pulses and oil-seeds, rice followed by chick-pea, maize followed by chick-pea, sorghum or green gram followed by safflower or sorghum- chick-pea and maize-chick-pea.
These break up the slope.
Intercept runoff before its volume and velocity become sufficient to cause serious erosion
gives more time for infiltration
water is diverted into the channels down safe gradients of suitable discharge or outlet points which carry away water in such a way as to minimize erosion damage to other land and
Finally leading to better conservation of run-off water for agriculture.
The bund section is 1.61 m2 in Vertisols and 1.05 m2 in Alfisols. The vertical distance is about 0.9 m. The area occupied is upto 5.0 per cent by the bund and the area lost from cultivation due to stagnation in Vertisols would be 10 to 15 per cent.
Graded bunds are of 0.8 m2 cross section in Vertisols and at vertical internal of 0.7m with a channel on the upstream side. The area lost due to the structure would be not more than 3-5 per cent and there would be no water stagnation and graded bund with grassed waterways and box-type masonry drainage outlets in arable fields.
The practice of tie-ridging, where adjacent ridges are joined at regular intervals by barriers or ties of the same height, allows the water to infiltrate and prevent run-off except during intense storms. This method is adequate in moderate rainfall areas, except on very steep slopes.
On steeply sloping lands, the slopes where such terraces are found useful vary from 6 to 30 per cent. Bench terraces with 100 m length, longitudinal grades in the range of 0.2 to 0.8 per cent are recommended for Alfisols of high rainfall regions.
Ploughing across the slope and growing low value crops in catchment areas, the ploughing of deep soils should be done once in three to four years immediately after rabi crops. The light, shallow and medium soils should be hoed instead of ploughing which help to receive and retain moisture.
Reclaimation of Acidic Alkaline and Saline soils should be reclaim by adding lime, gypsum, sulphur, or pyrites respectively. Growing high value crops in level run-off concentrated strips and incorporating a liberal quantity of organic matter.
Maintenance of soil fertility and yield stability
Dryland areas have low yields and high yield fluctuations. The maintenance of soil fertility is a problem in such areas as for a considerable period of the year the soil remains uncropped and there is a loss of plant nutrients, loss of the fertile surface due to erosion leads to a decline in soil fertility to build up soil fertility and reduce the fluctuation of crop yield.
Conservation of soil and water in dryland areas are inter-related and where one is tried the other is also achieved.