Water regulation, crop production, and agricultural water management - understanding farmer perspectives on irrigation efficiency. (Special Issue: Irrigation efficiency and productivity: scales, systems and science.)

摘要

Irrigated agriculture is facing rising competition worldwide for access to reliable, low cost, high quality water. In England, farmers are under regulatory pressure to improve irrigation efficiency; indeed, demonstrating efficient water use is now a prerequisite for renewing an irrigation abstraction licence (permit). However, there are differences between the concepts of efficient water use as viewed by scientists, regulators and farmers, further confused by the overlap of similar terminology with both precise technical and wider less specific meanings. Most farmers' concepts of water efficiency are linked to maximising the farms' economic productivity rather than saving water per se, except perhaps when their own allocated resources may be inadequate. Using a financial criteria for water efficiency rather than an engineering one appears a sensible approach when assessing irrigation performance at the farm level, since any managerial (e.g. scheduling) and operational (e.g. equipment) inefficiencies associated with irrigation are implicitly included in the assessment. It also allows comparison between individual irrigators (benchmarking) and between different water sectors (e.g. agriculture, leisure, industry). However, estimating the direct financial benefits (value) of water to the farm is only part of the equation; assessing indirect economic benefits, such as the importance of irrigated production to the sustainability of rural communities is equally important, but much harder to achieve. Demonstrating efficient or 'best' use of water is not straightforward, but farmers and the water regulator need a rational approach that reflects the needs of the farming community whilst providing a policy framework for protecting the environment. This paper reviews the concept of irrigation efficiency in a temperate climate, considers the farmer perspectives, and supports using the 'pathway to efficiency' as a means to assist farmers and the water regulator in achieving better irrigation management and abstraction control.