Management options to mitigate the adverse effects of aberrant weather can minimise the risk of total crop failure.
Late Onset of Monsoon:
Crops and varieties recommended for normal onset of monsoon may not be remunerative for delayed sowing due to late onset of monsoon. Two management options under these circumstances are transplanting and alternate crops/varieties.
Transplanting:
Community nurseries under irrigation are the sure way of compensating delay in monsoon. Transplanting can be taken up with the receipt of rains. Finger-millet, pearl-millet and setaria (foxtail-millet) are well adopted to transplantation.
Alternate Crops/Varieties:
Certain crops and varieties can perform better even if sown late in the season. Depending on the receipt of rains, such crops and varieties can be selected. Castor is more remunerative in red soils of Telangana (AP) than pigeon-pea under late sown conditions.
Sunflower, because of its shorter duration, performs better than groundnut when sowings are delayed beyond September first fortnight in relatively deeper red soils. In western Rajasthan, short duration green-gram and cowpea are more remunerative than pearl-millet when sown late. Crops and varieties for different dryland regions have been identified for late onset of monsoon.
Dry Spells during Crop Period:
Dry spells during crop period are common in dryland agriculture. The adverse effect of moisture stress should be mitigated to avoid total crop failure.
Ratooning/Thinning:
The rate of soil moisture depletion increases with increasing leaf area. If drought occur at 40-50 days after sowing, reduction in leaf area either by ratooning or thinning the plant population can mitigate the adverse effects of drought. Sorghum and pearl-millet responds to ratooning. Two per cent urea spray after drought period is useful for indeterminate crops like castor, pigeon-pea and groundnut.
Mulching:
Surface mulching with organic materials can extend the period of water storage in soil profile by minimising the heat load on soil leading to reduction in evaporation loss of stored water.
Repeated inter-cultivations in black soils results in formation of soil mulch on the surface. It act as a barrier to evaporation loss from soil profile. Deep cracks formed due to drought increase the loss of stored water by evaporation. Soil mulch minimise deep cracking leading to reduced evaporation losses.
Weed Control:
Weeds compete with crop for nutrients, water and other natural resources. Such competition for soil water from weeds can be reduced by timely weed control.
Water Harvesting and Protective Irrigation:
In situ water harvesting and protective irrigation are the potent measures of crop life-saving during periods of soil moisture stress.
Early Withdrawal of Monsoon:
Early withdrawal of monsoon before rabi seeding leads to problems of crop stand establishment and terminal drought. Therefore, rabi seeding should be as for as possible in early September to avoid the above two problems. All the suggested measures to mitigate the adverse effect of prolonged dry spells during crop period are necessary to overcome the soil moisture stress due to early withdrawal of monsoon.
Extended Monsoon:
Extended monsoon is seldom a problem in dryland agriculture. It benefits long duration kharif crops taken as a component crops in intercropping system and also advantageous for rabi crops in Vertisols.