Department of Agronomy, Acharya N.G. Ranga Agricultural University, S.V. Agricultural College Campus, Tirupati-517 502, Andhra Pradesh, India
When water supplies are restricted, so that full evapotranspiration demands cannot be met, limited irrigation is practised. Management strategy of limited irrigation is to optimise production per unit of applied water rather than to maximise yield per unit of land. Principles that help to facilitate limited irrigation strategies can be broadly grouped into three: agricultural water management, crop considerations and agronomic options. When anticipating low water year, choose crops which maximise production with limited water. In decreasing order of efficiency, short season indeterminate and long season indeterminate crops should be chosen judiciously. Deficit irrigation practices, localised irrigation methods, reducing water losses, conjunctive use of water resources etc can help minimise yield losses due to soil moisture stress. Additional agronomic management options that can maximise production include conservation tillage, advancing or delaying planting dates in order to coincide the crop's critical period with water availability, decreasing plant competition by reducing seeding density and controlling weeds. Available options to address the challenge of limited irrigation have been briefly presented.
Conjunctive use of water resources, Deficit irrigation, Limited irrigation, Water productivity, Yield response factor
