What is Rainfed Agriculture?
Definition: Dryland Agriculture refers to the growing of crops entirely under rainfed conditions.
Based on the amount of rainfall received, dryland agriculture (Rainfed Agriculture)can be grouped into three categories:
1. Dry Farming:
Cultivation of crops in areas where average annual rainfall is less than 750 mm per annum. Crop failure is most common due to prolonged dry spells during the crop period. These are arid regions with a growing season (period of adequate soil moisture) less than 75 days. Moisture conservation practices are necessary for crop production.
2. Dryland Farming:
Cultivation of crops in areas receiving rainfall from 750 to 1150 mm per annum. In spite of prolonged dry spells crop failure is relatively less frequent. These are semi-arid tracts with a growing period between 75 and 120 days. Moisture conservation practices are necessary for crop production. However, adequate drainage is required especially for vertisols or black soils.
3. Rainfed Farming :
Cultivation of crops in regions receiving more than 1,150 mm per annum. Crops are not subjected to soil moisture stress during the crop period. Emphasis is often on the disposal of excess water. These are humid regions with a growing period of more than 120 days.
What are the problems and prospects of Rainfed Agriculture?- In India as well in the world
Problems or constraints for crop production in rainfed farming regions Most of the cropping in the arid and semi-arid regions continues to be under rainfed conditions. A majority of the farmers are small farmers with meager resources. The poor resource base permits only low input subsistence farming with low and unstable crop yields. The low productivity of agriculture in rainfed farming regions is due to the cumulative effect of many constraints for crop production. The constraints can be broadly grouped into.
1) Inadequate and Uneven Distribution of Rainfall:
In general, the rainfall is low and highly variable which results in uncertain crop yields. Besides its uncertainty, the distribution of rainfall during the crop period is uneven, receiving a high amount of rain, when it is not needed, and lack of it when the crop needs it.
(a) Cultivation of low water required crops
(b) Short duration crops grown
(c) Providing life-saving irrigation
2) Long Gap in Rainfall :
(a) Increase in seed rate to obtain more population
(b) Spraying of urea solution
(c) Providing life-saving irrigation at critical growth stages
(d) Weeding and intercultural operations
3) Early Onset of Monsoon :
(a) Cultivate Pearlmillet, Sesamum etc.
4) Late Onset of Monsoon :
Due to the late onset of monsoon, the sowing of crops is delayed resulting in poor yields.
(a) Alternate crop &varieties: Castor (Aruna), green gram, cowpea, sunflower
(b) Dry sowing
(c) Pre sowing
(d) Seed soaking/treatment
(e) Transplanting of one-month-old Bajra seedlings.
(f) Complete weed control
(g) Grow legumes/oilseed crops in place of cereals
(h) The most suitable crop for this condition is Sunflower.
5) Early Cessation of Rains :
Sometimes the rain may cease very early in the season exposing the crop to drought during flowering and maturity stages which reduces the crop yields considerably
(a) Select short duration varieties
(b) Using mulching/mulches
(c) Life-saving irrigation applied
(d) Decrease in plant population
6) Prolonged Dry Spells :
Long breaks in the rainy season is an important feature of the Indian monsoon.
These intervening dry spells when prolonged during crop period reduces crop growth and yield and when unduly prolonged crops fail.
(a) If dry spell in 10 days of sowing, resowing
(b) If mild moisture stress at 30-35 days after sowing, thinning of alternate rows of Sorghum and Pearl millet
(c) If severe moisture stress at 30-35 days after sowing, cutting of sorghum and Pearlmillet and rationing
(d) If moisture stress at blooming stage, cutting of sorghum and Pearlmillet and rationing
(e) Breaking of monsoon for short while, shallow inter cultivation for eradicating weeds/soil mulch
(f) Wider spacing for moisture conservation
(g) Spray of 2 percent urea after drought period is useful for indeterminate crops like castor, pigeon pea, and groundnut.
(h) Soil mulching to reduce evaporation losses
(i) In situ water harvesting
(j) Life-saving irrigation
(k) Weed control to save water, nutrients, etc.
7) Low moisture retention capacity :
The crops raised on red soils, and coarse-textured soils suffer due to lack of moisture whenever prolonged dry spells occur due to their low moisture-holding capacity. Loss of rainwater occurs as runoff due to undulating and sloppy soils.
8) Low fertility of soils :
Soil fertility has to be increased, but there is limited scope for extensive use of chemical fertilizers due to lack of adequate soil moisture.