| A field experiment was conducted in Wenxi County, Yuanqu County, Wanrong County, in Southern Shanxi from July 2011 to July 2014 ?three consecutive years?, in which selected 20 pilot sites to study wheat yield in different precipitation years; we selected two pilot sites respectively to carry out the experiment of nitrogen, phosphorous fertilizer varieties test in Wanrong County, Yuanqu County to study the effect of different fertilizers on yield in different precipitation years; and selected a test point to experiment with the nitrogen, phosphorus application rate in Wenxi to study the optimum supplies of nitrogen and phosphorus application rate in dryland wheat in different rainfall years. Three experiments were conducted to insight into dryland wheat yield in different areas of Jinnan, the nitrogen and phosphate fertilizer varieties and application amounts to be most conducive to the wheat yield, and better adjust measures to local conditions. It is essential to research wheat yield of the whole province and even throughout the north. The main results are as follows:1 The difference of dryland wheat yield in southern ShanxiYield and the average annual yield are characterized by the highest in humid year, normal rainfall year middle, the lowest in dry year among each test point in Wenxi, Yuanqu County, Wanrong County; the highest yield trial points are Qiujialing village Tongcheng town, Lujiapo village Changzhi town, Xinsi village Huangpu town in Wenxi Yuanqu County, Wanrong County, respectively; the average annual yield among each test point were 2185-3243 kg·hm-2,1760-2980 kg·hm-2,1165-1662 kg·hm-2, respectively. The three-year average yield of three counties were 2508 kg·hm-2,2761 kg·hm-2,1451 kg·hm-2. The yield of Yuanqu is 10% higher than that of Wenxi, and 90% higher than the Wanrong County. Compared with Wanrong County, the yield of Wenxi is 73% higher. Therefore, wheat yield is affected by annual precipitation change greatly among Yuanqu, Wenxi, Wanrong County. If the rainfall is abundant, the yield is high, otherwise, the yield is low. The yield level has larger distance than the average yield level of the winter wheat (4700 kg·hm-2).The rate of increase in dryland wheat yield in Wanrong County is the highest, reaching 87% -95%; Wenxi County, compared with Wanrong County, is in the middle up to 51% -83%; Yuanqu County is the smallest, reaching 3%-24%. In the three-year precipitation, the yield-increasing effect in Yuanqu County, compared with Wanrong County, is biggest in humid year, which did not significantly reduced in 2012-2013; compared with Wanrong County, Wenxi County is not prominent when humid year and when normal year basically flat, but when dry year greatly reduced; compared with Wenxi County, Yuanqu County is the biggest in 2012-2013, but lower in 2011-2012,2013-2014. Therefore, dryland wheat yield in Yuanqu County is the most stable, however, Wenxi County is the most unstable in dry year, and not prominent in humid and normal precipitation year.2 Effect of nitrogen fertilizer on dryland wheat in southern ShanxiThe effects of nitrogen fertilizers on the yield and its composition, economic coefficient were consistent, which showed urea> diamine phosphate> carbon amine> diamine. And four kinds of nitrogen fertilizers had no significant difference in Linchang village Maojiawan Town Yuanqu County, diamine and other nitrogen fertilizers had significantly difference in Lujiapo village Changzhi Town Yuanqu County, Xinsi village Huangfu Town Wanrong County, Nanpo village Hanxue Town Wanrong County. Hence, the yield had a certain difference among nitrogen fertilizer varieties, the effect of urea application alone is the best, diamine worst, which mainly because fertilizer nutrient leaching was closely related with the varieties of fertilizer, nutrient forms, fertilizer amount and fertilization methods.The effect of nitrogen application rate to yield and water use efficiency had differences due to different precipitation. With the increase of nitrogen application rate, yield and its composition, biomass and economic coefficient in humid year improved gradually, and N225 up to the highest; in normal year increased at first and then decreased, N150 reached the highest; dry year increased at first and then decreased, N75 reached the highest. Obviously, the nitrogen application rate is determined by precipitation, there is significant interaction between moisture and nitrogen, which are regulated yield components to affect the yield and water use efficiency ultimately3 The effect of phosphate fertilizer on dryland wheat in southern ShanxiThe effect of phosphate fertilizers on yield and its components, biomass, economic coefficient had little differences, the yield and its component factors, biomass, economic coefficient indicated that superphosphate was higher than nitric phosphate in Linchang village Maojiawan Town Yuanqu County, Xinsi village Huangpu Town Wanrong County, Nanpo Village Hanxue Town Wanrong County, but in Lujiapo village Changzhi Town, economic coefficient in normal rainfall year with high phosphorus nitrate, and has not significant differences among varieties of the same year. Obviously, the yield among phosphate fertilizer had certain differences, but little difference. Only two kinds of phosphate fertilizer varieties does not possess accuracy, thus need to further study in increasing fertilizer varieties and different proportion of mixed application about the effect of different phosphate fertilizer varieties on yield.The effect of phosphorus application amount on yield of dryland wheat was consistent. With the increase of phosphorus application rate, the yield and its composition, biomass ?except for dry year?, the economic coefficient increased first and then decreased, and P150 reached the highest. There were differences in the regulation of water consumption in different precipitation years, which was consistent with the regulation effect of the water use efficiency. With the increase of phosphorus fertilizer application, in humid year water consumption, water use efficiency increased at first and then decreased, P150 up to the highest; in normal rainfall year, water consumption in whole growth period of and water use efficiency increased at first and then decreased, P150 up to the maximum; in dry year water consumption in growth period increased at first and then decreased, P75 up to the highest, and water use efficiency also increased at first and decreased P150 was the highest. Compared to the optimum amount of phosphorus in different rainfall years, according to water use efficiency calculated the annual water consumption, dry year in the highest level, normal rainfall year in the middle, humid year minimum; however, according to water use efficiency calculated water consumption in the growth stage, normal rainfall year is the highest, humid year in the middle, dry year in the lowest. Obviously, the optimum amount of phosphorus application in dryland wheat production in southern Shanxi was 150 kg·hm-2. |
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