Wheat yield

To promote the use of poor quality water for irrigation, a field research study was conducted in three semi-arid regions with water scarceness in Syria in order to define, under field conditions, the wheat yield response function to irrigation water salinity, the effect of soil texture and structural characteristics on the irrigation water salinity threshold, and to compare this value with the conventional threshold value. 

Field beans grow well on clay soils and heavy loams, provided they are well-drained and limed (pH above 6). Winter beans are not frost hardy and so are risky to grow, north of the Midlands. In some rotations, beans replace the clover break and they are usually followed by wheat. Yields for spring and winter field beans are shown in Table 5.4. The problem with field beans is their variable yield, which is partly caused by adverse weather conditions and susceptibility to pests and diseases (winter beans get chocolate spot, spring beans are aphid prone), and partly due to the uncertain activity of the necessary insect crosspollinators. 

Some assets are difficult to cost accurately for example, the notional financial value of providing a haven for wildlife, or of keeping your part of the river free from excess nitrates. Another example would be the value of keeping beef cattle indoors and then using the farmyard manure to improve soil structure and maintain wheat yield. 

Barbarick K.A., Ippolito J.A. Termination of sewage biosolids application affects wheat yield and other agronomic characteristics. Agron J 2003 95 1288-1294. 

Organic solvents and water extracts prepared from monoculture wheat soils under conventional tillage (CT) and no tillage (NT) indicated that both soils contain some inhibitory compounds. The CGC/MS/DA of some of the organics is presented. Selected organics from CT and NT as well as allelopathic and autotoxic effects are described and discussed. The relationship between the wheat yields in CT and NT and the possible biological stress is indicated. 

Brunetti, G, Senesi, N., and Plaza, C. (2007a). Effects of amendment with treated and untreated olive oil mill wastewaters on soil properties, soil humic substances and wheat yield. Geoderma 138,144-152. 

These predictions have caused much concern in North America. Sharp decreases of corn and wheat yield from the major granaries of the mid-west and Great Plains (Abrahamson, 1983) have been seen as a likely outcome, because these crops are already grown at temperatures above their optima,... 

Up to that point, safflower seed production had been on a continued upward spiral in the United States, which carried through to 1963. Safflower oil had been price competitive with soybean oil, particularly in the western United States and Japan, since soybean oil produced in the Midwest was at a freight disadvantage. The introduction into California of new varieties of wheat developed by the Borlaug program in Mexico allowed California farmers to achieve increasingly better wheat yields. In the 1950s, safflower was easily able to compete with wheat or barley as a rotation crop for California s rice or cotton farmers, but once wheat yields increased and safflower yields remained constant, safflower seed prices (and consequently oil prices) were forced to rise to compete for the farmer s favor. 

Table V. Effect of Epibrassinolide on Wheat Yield in China...

Five parts of white plus the 1 part of wheat yields a 6 part mixture. Let x = the number of pounds of white flour present in a 48 lb mixture. Thus, the problem can be restated more usefully as 5 parts is to 6 parts as x pounds is to 48 pounds, or = y. Cross multiplying (5)(48) = 6x x = —g—. Thus x = 40, choice d. 

Coventry et al. (1987) reported increases in wheat yields due to added Mo in 2 of the 5 years in their study, but increases in grain weight and N content in 3 of the 5 years. Leaf N was increased during one of those years because of addition of lime, which they assumed to have caused increased mineralization of N and increased availability of Mo, which would have facilitated assimilation of N. That site was also reported to have insufficient Mo for growing subterranean clover (Coventry et al., 1985). 

The residual effects of applied Mo will vary for different soil types, and Mo may have to be applied annually. Riley (1987) summarized the data from a 3-year study and reported that Mo applied at a rate of 75gha would give, during the second year, only 86% of the yield seen during the first year. But the residual effects of Mo application at a rate of 140gha" gave maximum wheat yields for 15 years. The decline in the... 

Comparisons of stubble mulch with complete chemical fallow systems of farming have usually given results that favor the former system. For example. Black and Power (1965) reported that wheat yields on stubble-mulched soils were higher than where spray was used. Furthermore, neither chemical fallow nor combinations of chemical and mechanically-tilled plots resulted in more moisture conservation than with conventional stubble mulch. Wind erodibility was, however, less with complete chemical fallow soils, doubtless because of complete absence of tillage. 

Figure 13.10 Wheat yield growth by world regions (5-year moving averages in percentages). ( nova-lnstitut...

Ehukov, I. L, Biryukova, O. A. Kryschenko, V. S. (2009). The multidiagnostic value for the prediction of winter wheat yield and optimal content of available phosphorus in calcareous chernozem. Agrochemicals, 11, 7-15. 

Fig. 2. UK national average winter wheat yield, nitrogen fertilizer usage and proportion of crops treated with CCC (Data for 1979 and 1981 are not available). Sources Ministry of Agriculture, Fisheries and Food (yields). Fertilizer Manufacturers Association (nitrogen), ICI (CCC)...

In this variant for 12-year-long aftereffect of fertilizers winter wheat yield (on the average for tree rotations) was 17.2 centner per hectare as compared with 12.0 centner per hectare in the control variant. So due to... 

Yellow wheat blossom midge affects wheat yield more than quality as they feed on the anthers and prevent grain fertilisation. 

Wheat yields have plateaued overthe lasttenyears (Table 13.11). Yields have also fluctuated across the eountiy mainly due to variations in rainfall. 

Separation of flours into high-protein and low-protein fractions—In the past, high-protein hard wheats were used to make flours suitable for yeast-leavened doughs and low-protein soft wheats yielded flours for quick breads. Now, either type of wheat may be milled and separated into high- protein and low-protein fractions by swirling streams of air in a process called air classification. This procedure enables millers to produce flours to meet customers requirements. 

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