Madar Samad

Opportunities and limitations of food–feed crops for livestock feeding and implications for livestock–water productivity

The paper discusses the contribution of crop residues (CR) to feed resources in the context of the water productivity of CR in livestock feeding, using India as an example. It is argued that crop residues are already the single most important feed resource in many livestock production systems in developing countries and that increasing their contribution to livestock feeding needs to be linked to improving their fodder quality. Using examples from multi-dimensional crop improvement, it is shown that CR fodder quality of key crops such as sorghum, rice and groundnut can be improved by genetic enhancement without detriment to grain and pod yields. Improving crop residue quality through genetic enhancement, agronomic and management interventions and strategic supplementation could improve water productivity of farms and systems considerably. The draw-backs of CR based feeding regimes are also pointed out, namely that they result in only moderate levels of livestock productivity and produce higher greenhouse gas emissions than are observed under feeding regimes that are based on high quality forages and concentrates. It is argued that feed metabolisable energy (ME) content should be used as an important determinant of livestock productivity; water requirement for feed and fodder production should be related to a unit of feed ME rather than feed bulk. The paper also revisits data from the International Water Management Institute (IWMI) work on livestock–water productivity in the Indian state of Gujarat, showing that water input per unit ME can vary several-fold in the same feed depending on where the feed is produced. Thus, the production of one mega joule of ME from alfalfa required 12.9 L of irrigation-derived water in south Gujarat but 50.7 L of irrigation-derived water in north Gujarat. Wheat straw in south Gujarat required 20.9 L of irrigation-derived water for 1 MJ ME and was in this instance less water use efficient than alfalfa. We conclude that water use efficiency across feed and fodder classes (for example crop residue v. planted forages) and within a feed is highly variable. Feeding recommendations should be made according to specific water use requirement per unit ME in a defined production system.

An Assessment of the Impact of Participatory Irrigation Management in Sri Lanka

This paper presents the results of a study on the effects of participatory irrigation management in Sri Lanka. The study is based on the application of a methodology developed by the International Water Management Institute (IWMI) to assess the impact of irrigation management transfer on the performance of irrigated agriculture. Performance is measured from several perspectives: financial, irrigation management, and agricultural productivity levels. Piecewise linear regression models are fitted to compare trends in performance during the five-year period before transfer and five years after. The results show that there has been a significant drop in governments recurrent expenditure for irrigation over time. The decline is not confined to schemes where participatory management had been introduced but to other schemes as well. The cost of irrigation to farmers has remained the same before and after transfer. The analysis reveals that irrigation management transfer alone did not bring about significant imp...

ASSESSMENT OF THE LIVESTOCK-FEED AND WATER NEXUS ACROSS A MIXED CROP-LIVESTOCK SYSTEM'S INTENSIFICATION GRADIENT: AN EXAMPLE FROM THE INDO-GANGA BASIN

Projections suggest that annual per capita water availability in the Indo-Ganga Basin (IGB) will reduce to a level typical for water-stressed areas. Producing more crop and livestock products, per unit of agricultural water invested, is advocated as a key strategy for future food production and environmental security in the basin. The objective of this study was to understand the spatio-temporal dynamics of water requirements for livestock feed production, attendant livestock water productivity (LWP) and implications for the future sustainable use of water resources. We focused on three districts in the IGB representing intensive (higher external inputs, e.g. fertilizer, water) and semi-intensive (limited external input) crop-livestock systems. LWP is estimated based on principles of water accounting and is defined as the ratio of livestock beneficial outputs and services to the water depleted and degraded in producing these. In calculating LWP and crop water productivity (CWP), livestock, land use, land productivity and climatic data were required. We used secondary data sources from the study districts, field observations and discussions with key informants to generate those data sets. Our result showed that the volume of water depleted for livestock feed production varied among the study systems and was highly affected by the type of feed and the attendant agronomic factors (e.g. cropping pattern, yield). LWP value was higher for intensive systems and affected by agricultural water partitioning approaches (harvest index, metaolizable energy). LWP tended to decrease between 1992 and 2003. This can be accounted for by the shift to a feeding regime that depletes more water despite its positive impacts on animal productivity. This is a challenging trend with the advent of and advocacy for producing more agricultural products using the same or lower volume of water input and evokes a need for balanced feeding, by considering the nutritive value, costs and water productivity of feed, and better livestock management to improve LWP.

Phases of river basin development: the need for adaptive institutions.

In Svendsen, Mark (Ed.). Irrigation and river basin management: options for governance and institutions. Wallingford, UK: CABI; Colombo, Sri Lanka: International Water Management Institute (IWMI).

Assessing the outcomes of IWMI’s research and interventions on irrigation management transfer

In Waibel, H.; Zilberman, D.EC (Eds.). International research on natural resource management: Advances in impact assessment. Rome, Italy: FAO; Wallingford, UK: CABI