Since livestock are universally valued for income and investment purposes, they cannot be excluded from irrigation schemes. Although many such schemes fall in the Arid Zone, many others are in the SAZ, and there are no fundamental differences. The following observations are salient:
(1) Investment in irrigation development not only attracts an increased human population to the site, but also causes a concentration of livestock from surrounding areas, as migration occurs, and encourages an increased investment in animals (if the scheme produces profits).(2) Local natural grazing resources soon become inadequate to support the increased numbers of livestock, initiating processes of degradation.
(3) Irrigated crops offer a potential increase in the amount of crop residues available for livestock, and there are incidental benefits, such as canal-side grazing.
(4) Livestock tend to be regarded by project managements as a menace, since they may, if carelessly managed, cause damage to irrigation works, and create coordination problems in integrating cropping cycles with access to residues, thereby damaging crops.
(5) These problems tend to be resolved by sending livestock off the scheme for a part or all of the year, supervised by hired herders.
(6) The risks that accompany intensified market integration on irrigation schemes tend to strengthen the perceived value of livestock ownership as a form of insurance as well as a way of investing profits; but intrinsic incompatibilities between capitalised irrigated farming and under-capitalised livestock husbandry may result in a low level of crop-livestock integration, a physical separation of household crop and livestock enterprises, and a dominant view at the household level of cropping and livestock as alternative economic strategies.
Case Studies 7 and 19 illustrate the role of livestock on irrigation schemes.
