Regional Characteristics Of Grain Productivity And Chemical Fertilizer Use Efficiency In Main Grain Production Regions Of China

On the basis of our country's food security, how to advance the use efficiency of the agricultural resources especially that of the chemical fertilizer resources is a key to develop agriculture being of resources saves and environment health. Along with our national economy persistent and rapid increase, farmland conversion, population explosion,people's living standard improvement and the lasting increasing of per capita grain consumption, etc., the long-term food security has became a most important issue in present life and its basic outlet is to increase the grain productivity of per unit area continually. Among so many yield enhancement measures it is crucial to increase the agricultural resources especially the quantity of chemical fertilizer per unit area. However,the unreasonable chemical fertilizer application will not only waste the resources but also pollute the ecological environment. So studying the grain productivity variety traits in typical areas and researching the use efficiency of chemical fertilizer in typical areas could improve the decision-making references of our country's food security and distribution of fertilizer utilization. In the view of that, the paper, on the basis of collecting mass data and referring to the existing paper, makes a systematic analysis of grain productivity traits and chemical fertilizer use efficiency in our national main grain production region. The results were as bellow:The grain arable land productivity per unit area in southern and northem areas both had upward fluctuant trends. And no matter the average of the grain arable land productivity per unit area or the grain productivity per unit tilled land of Yangtze River middle reaches plain was still remarkably higher than other regions with the smallest CV and most steady value. In Northeast China Plain, the arable land productivity was highest but the farmland productivity was most unstable and the labour force productivity had a distinct advantage with a lowest point of 2.5t per individual. In Jiangsu province, each index, including the grain arable land productivity, the farmland productivity and the labour force productivity, were obviously higher than other areas. And the farmland productivity in Hubei took a second place. In 2004, the grain arable land productivity approximated 6t/hm~2 in Jiangsu and had a lowest point of 4.7t/hm~2 in Sichuan, which had the lowest increasing range approaching 50%; the farmland productivity average was lowest in Hubei with 4.7t/hm~2; the labour force productivity in Sichuan with the average of 1.1t per individual was obviously lower than the other two province in either average, maximum or minimum.The ratio of N, P, K had a similar trends in both Yangtze River middle reaches plain and Northeast China Plain: the phosphate fertilizer rate ascended after descending originally; the potassium fertilizer rate continuously increased quickly; and with a little different in North China Plain, the rates of both ascended rapidly. In 2004, the rates of phosphate fertilizer and potassium fertilizer were highest in Yangtze River middle reaches plain and lowest in Northeast China Plain. The phosphate fertilizer rate, which had significant difference between east and west, had small upward fluctuant but varied a little in Jiangsu and increased rapidly in Hubei and ascended after descending originally in Sichuan. And at the same period, the phosphate fertilizer rate in Hubei was far above both other provinces and the national level while the potassium fertilizer rate with Sichuan being the minimum in the three provinces was lower than the national level.The grain output rate under the fertilizer utilization had a similar trend in either northern or southern areas. It declined faster in 1980s and slowed down to decline in 1990s. And in North China Plain it was always lower than other regions. Due to the smallest decreasing range, it is highest in the Northeast China Plain. Compared with that in 1980, it decreased dramatically in all areas in 2004. It descended exceeding 50% in both North China Plain and Yangtze River middle reaches plain while descended least in Northeast China Plain, approximating 40%. The difference between east and west showed the similar trend with that between north and south. It was always lowest in Jiangsu and after 1987 it was highest in Sichuan all along and it was high in Hubei during the 1980s. Compared with that in 1980, it had a large decreasing range in all areas with the smallest decreasing range in Sichuan which exceeded 40%.Yangtze River middle reaches plain with the highest grain productivity had the priority in grain production in northern and southern areas. The labor force productivity was highest in North China Plain. Compared with other provinces, Jiangsu owned the highest grain productivity and was the prior regions. The second highest was Hubei province, whose farmland productivity and labor force productivity were higher than Sichuan.In contrary to other regions, North China Plain and Sichuan province owned higher monetary and grain output rates of fertilizer application, which could gain more profit under the same amount of fertilizer.