Grain Production And Grain Safety Of Loess Plateau

According to the grain problem which has long puzzled the Loess Plateau Region, thearticle developed the research of grain production and grain safety for two largegeomorphologic regions which were the loess hilly-gully region and loess gully region inthe Loess Plateau Region, analyzed the trend and influencing factors of grain production,studied the changes of grain production ecological cost in different spatial and temporalscale, to predict grain productiviy in different temporal scale, studied the changes of grainsafety of t in the Loess Plateau Region in different spatial and temporal scale, in order tosolve incoordination between ecological environment and economic development in thegrowth process of grain production and agricultural development, to impove the subjectresearch system, and to promote the sustainable development of grain safety and socialeconomy in the Loess Plateau Region. The main research results as follows:(1)The grain production of the Loess Plateau region influenced by population, grainarea, climate and policy had a stage fluctuation increasing trend. The grain production ofAnsai County in loess hilly-gully region could be divided into three phases from1949to2009. The first stage was from1949to1974, the second stage was from1975to1989, andthe third stage was from1990to2009. The average grain productions of three stages were1.89×104tons,3.72×104tons and6.1×104tons respectively. The grain production ofChangwu County in loess slope-gully region could be divided into three phases too from1949to2008. The first stage was from1949to1970, the second stage was from1971to1980, and the third stage was from1981to2008. The average grain productions of threestages were2.67×104tons,3.86×104tons and4.95×104tons respectively.(2)At county scale, the ecological cost of grain production was increased nearly threetimes, from to8.8726million yuan in1950to30.9815million yuan in2010at Ansai County of Loess Plateau Gullied-hilly; Comparison of Changwu County of Loess Plateau Gully, it was increased nearly two times, from to14.6102million yuan in1950to30.5886millionyuan in2008. For watershed scale, the ecological cost of grain production was reducedfrom to248,600yuan in1978to55,200yuan in2003at Zhifanggou watershed of LoessPlateau Gullied-hilly; Comparison of Wangdonggou watershed of Loess Plateau Gully, itwas reduced from to138,600yuan in1986to96,000yuan in2005.(3)In the county scale, the moving average period of the grain yield in Ansai Countyof loess hilly and gully region is20years. It is predicted that the average productivity willbe70600t by2019. The moving average period of grain yield per hectare is15years. It ispredicted that the grain yield per hectare will be2.342.34t/hm2by2019.The movingaverage period of the grain yield in Ansai County of the Loess Plateau is25years. It ispredicted that the average productivity will be53100t by2018. The moving average periodof grain yield per hectare is25years. It is predicted that grain yield per hectare will be3.86t/hm2by2018. For watershed scale, the moving average period of grain yield perhectare is15years, and the grain yield per hectare will be5132kg/hm2by2016.(4)Long-term fertilization could improve wheat yields, and combination of N, P andmanure increased yields largest, which were144.58%、209.29%、247.54%in threedifferent precipitation years. The contribution rate of fertilizers to wheat yields wereranked as: NPM>NM>NP>PM>M>N>P, and The contribution rate of fertilizers to wheatyields was higher in wet year than that in drought and normal year. The fertilizerinteraction of N and P fertilizer was highest, which was1906.95kg/hm2, and the next wasN, P and M, which was823.16kg/hm2. Fertilizers cooperating application could makewheat yields fluctuation in a high level, and the reason mainly come from the change ofprecipitation. Amount of fringe and weightiness of thousand grains were higher in wet yearthan that in normal and drought year, and the amount of fringe, grain of fringe andweightiness of thousand grains of combination of N, P and manure were highest in threedifferent precipitation years.(5)As to the comprehensive value of food security, in the county scale, the foodsecurity evaluation grades of the Ansai county in loess hilly and gully region, and of theChangwu county in loess gully region, both have experienced the change from poor togood; in watershed scale, the food security status of Zhifanggou watershed in loess hillyand gully region in2003was in the middle grade, and it of Wangdonggou watershed inLoess Gully Region rose to good in2005from above the average (upper-middle-class/thehigh middle grade) in1986.