BBE
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he practice of water-conservation methods such as terracing, contour tillage, andstrip cropping benefitted pasturage yield to a measurable extent but showed no significantrelation to grain yield. Stubble mulching, on the other hand, depressed yield of grain without affecting pas-ture yield. The value of stubble mulching may depend on its efficiency in preventing winderosion and conserving moisture, factors which often compensate for a slight loss ofyield. Total rainfall coming during the grazing period did not affect yield of pasturage butwas very positively related to subsequent grain yield. However, excessive rain as indi-cated by a high weekly rate of rainfall during both preparatory period and grazing periodreduced grain yield, yet affected pasturage yield during the preparatory period only.These reactions to wet and dry periods are best explained by the highly significant nega-tive simple correlation (-0.279) between rates of rainfall in the summer preparatoryperiod and the following fall and winter grazing period. The fact that a wet summer wasusually followed by a dry fall during this particular period of observation (1946-51) doesnot make this a permanent rule, but simply explains the moisture relations observed inthis study. Initial amount of soil-stored water affected favorably the yields of both pasturage andgrain. The most common planting date was about mid-September, just 1 month before therecognized most favorable date for grain yield. This reflects strongly the prevailing ideaof early sowing to enhance pasturage. Extremes ranged between late August and earlyNovember. Statistical treatment showed no significant correlation between sowing dateand pasturage yield, but long-time experiments which show late seeding within this rangeto be favorable to higher grain yields were confirmed. Therefore, early sowing does notenhance pasturage. Length of grazing period naturally was highly correlated with forage dry matter re-moved, but was significantly correlated to reduced grain yield. Finally, there was no significant dependence of grain yield on amount of pasturagetaken from the fall and winter growth of wheat. It should be pointed out that these observations were obtained from average farmersoperating in the manner to which they were accustomed; a manner which includes suchpractices as taking cattle off of muddy land and ending the grazing season before wheatjoints begin to lengthen noticeably in the spring. The general conclusion from this study, covering a period in which wheat yields werea little better than average, is that grazing can be practiced with commonly accepted pre-cautions without harm to the land or substantial reduction of grain yield. Fall and wintergrazing of wheat in the Southern Winter Wheat Regions, therefore, should be recognizedas a productive practice. Its feasibility need not depend on conditions more difficult tosatisfy than providing for necessary fencing and water. These statistics indicate that undue lengthening of the grazing period should be avoided. It was apparently not the amount of forage removed by grazing but length of timethe grazing period was extended that reduced grain yields.
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