固原30年粮食产量变化及技术进步贡献的数量分析

The Variation Features of Grain Yield in Guyuan County in Recent 30 Years and the Contribution of Associated Factors

运用时间序列与多元回归分析法，对固原县３０年粮食单产变化及技术进步贡献进行了较系统的分析，结果表明：（１）该县粮食产量在３０年中经历了三个阶级：６０年代中后期，单产徘徊于４５０～７５０ｋｇ／ｈｍ２，技术退步，导致减产的贡献显著大于气候不利造成减产的贡献。７０年代至８０年代初，单产在７５０～１２００ｋｇ／ｈｍ２徘徊，并有其技术水平对产量增加的贡献为４６％，接近于气候不利带来的负增产（５４％）。１９８３年至１９９３年，粮食有明显增长，单产基本稳定进入１２００ｋｇ／ｈｍ２。技术水平对产量增加贡献占７９．２％，而气候不利的负增产仅占２０．２％，技术水平的贡献明显大于气候的影响。（２）从１９７０年始，粮食单产变化中各技术水平因子的贡献分别为：良种３２．２％、化肥２６．５％、牧业与农肥２４．４％，农田基建１６．８％．在１９８３～１９９３年间，技术进步占到单产提高的４８．６７％、生产条件改善为３１．１３％，其余为气候带来的负增产贡献。

The long historical unit grain yields in Guyuan were analysed by using single factor's muti-times regression, and muti-factors regression, the variation features of unit yield in recent 30 years and thier relationships with the associated factors were also analyzed. The results show that:① The variation classed into three stae: In mid-late 60's nit yield variated around 450-750kg/hm2, with technique r retrogression and unfitable climate. In 70's￣80's, unit yield fluctuated around 750-1 200kg/hm2, with some technique's development. In late 90's the unit yield reched at 1 200kg/hm2 with the laryely contribution of technique's development ②Began at 1970, the contribution factors of technique on unit yield's variation are that: among total contribution of technique factors, poultry(manure) 24. 4%, chemical fertilizer 26. 5 %, improved varieties 32. 2 %, terrace field 16. 8%. during 1983￣ 1993, Influence of factors on increesing unit yield was divided as fallow: 48. 67% was from technique development, 31. 13% was contributed by improved produce condition, and others 20. 2% came from oscillated climate.