PART VII — WATER RESOURCES, FORESTRY, AND AGRICULTURE 



to base these decisions. To do so we 

 would need to bring together the 

 scattered record of climate, the frag- 

 mentary knowledge of soil, the dis- 

 persed experience with varieties and 

 breeds, and the complex measure- 

 ments of the impact of cultivation or 

 grazing practice on available soil 

 moisture. Within a framework of 

 water-balance accounting, simulated 

 traces of climatic data can provide 

 probabilities of moisture availability 

 directly related to specific varietal 

 needs or stocking patterns. If these 

 probabilities are used as appropriate 

 weights in programming models, crop 

 yields may be balanced against 

 drought risk, desirable planting times 

 determined, or the role of labor- 

 or capital-intensive moisture-conserv- 

 ing practices assessed. 



A special role for the use of such 

 data is for the planned agricultural 

 settlement. Wherever men are in- 

 duced to move to new, often strange 

 environments, greater drought risks 

 are often incurred as a function of 

 their ignorance. The dust bowls of 

 the American West, the Virgin Lands 

 of the Soviet Union, and the Ground- 

 nuts Scheme of colonial Tanganyika 

 provide tragic evidence of the uni- 

 versal cost of learning about new 

 environments even with, or perhaps 

 because of, the application of consid- 

 erable technology. Thus, much might 

 be done for both the indigenous and 

 pioneer agriculturalist through the 

 assemblage of the available data base, 

 through the identification of missing 

 information by systems analysis, 

 through the filling of critical gaps by 

 experiment and field research, and 

 through the distillation of the final 

 product in such form as to provide 

 meaningful answers to the perennial 

 questions of farmers, ranchers, and 

 planners be they peasant or agro- 

 industrial producers. 



Water-Saving Cultivation — A 

 number of the critical gaps in our 

 knowledge have already been identi- 

 fied. For example, data on water- 

 yield relationships in less than opti- 

 mal conditions are difficult to obtain. 



We know for most plants how much 

 water they need to survive and how 

 much water they can use if water is 

 readily available, but we know little 

 about the trade-off between these two 

 points. The breeding of new varieties 

 has, to date, seemed to require more 

 rather than less water for the high- 

 yielding varieties; there seems little 

 widespread exploration in breeding 

 of the balance between yield and 

 water need. 



Though some water-saving cultiva- 

 tion methods are widely practiced, 

 the actual effects of some measures 

 are disputed, partly because these 

 effects seem to vary greatly with soil, 

 slope, rainfall, and cultivation prac- 

 tice. For example, tie-ridging, a wa- 

 ter-conserving practice in semi-arid 

 tropical areas has a very mixed effect 

 depending on the crop, soil, slope, 

 and pattern of rainfall encountered. 

 The proper timing of planting or 

 grazing requires much more analysis. 

 The probability of below-average 

 rainfalls that might lead to drought 

 is calculated in certain standard ways, 

 usually involving the assumptions 

 that rainfall events are independent 

 and that the relative frequency or 

 some mathematical isomorphism of 

 historic events provides useful prob- 

 abilities of future expectation. But 

 neither of these approaches ade- 

 quately forecasts the persistence of 

 below-normal rainfall characteristic 

 of drought conditions in temperate 

 areas or the monsoonal delays asso- 

 ciated with drought in tropical areas. 

 Forecasts of persistence require 

 knowledge of the climatic mechan- 

 isms associated with the phenomenon 

 and forecasts of monsoonal delay re- 

 quire understanding of the associated 

 weather systems. 



Irrigation — For a considerable part 

 of the world, irrigation represents a 

 crucial drought adaptation. But ir- 

 rigation efficiency is notoriously low; 

 the amount of water wasted prior to 

 field application from conveyance, 

 seepage, phreatophytes, or in misap- 

 plication is very high. For all of 

 these sources of water loss, the po- 



tential contribution from applied re- 

 search is great. 



Nevertheless, in many parts of the 

 world, water availability is far in 

 advance of water utilization because 

 farmers are slow to adopt the new 

 system. It is with irrigation, as with 

 the adoption of new hybrids or in the 

 choice of any new adjustment, that 

 the social sciences have a special 

 role in bridging the technical isolation 

 that characterizes much research and 

 development and in placing such 

 efforts into the ecological matrix of 

 farmers' life styles, agricultural sys- 

 tems, and socio-institutional settings. 

 For many farmers, acceptance of ir- 

 rigation literally means the accept- 

 ance of a new way of life. Thus, the 

 question is still wide open as to which 

 farmers make the best settlers for 

 the great new irrigation projects now 

 on the drawing boards of many de- 

 veloping countries. Or consider the 

 achievements of the Green Revolu- 

 tion. We are told that the rapid 

 adoption of high-yielding rice and 

 wheat, particularly in South Asia, 

 will give needed breathing space in 

 the critical Malthusian struggle for 

 survival. But we are warned that 

 such adoption comes at a cost of 

 further stratifying rural society and 

 intensifying existing trends that cre- 

 ate classes of prosperous landowners 

 and landless rural workers. An even 

 more complex social interaction is 

 found among farmers on the shores 

 of Lake Victoria who seem to be 

 shifting from drought-resistant millet 

 to bird-resistant maize because their 

 children, who formerly stayed in the 

 fields at harvest time to protect the 

 crops from bird pests, are now in 

 school! 



All of the foregoing, the propen- 

 sity to adopt innovations, rural class 

 stratification, even bird pests, are 

 factors capable of analysis, if not 

 solution, within a framework of hu- 

 man ecological systems analysis. But 

 just as plant breeders have had to 

 develop strategies of genetic change 

 and varietal development capable of 

 providing new strains quickly, so 



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