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在亚巴拉马州田纳西流域,对棉花生长期的三种耕作法,在天然降雨条件下引起的地表径流和土壤流失进行了小区试验研究.传统耕作法产生的土壤流失量最大,其次是少耕法无覆盖和少耕法有覆盖(冬小麦覆盖作物).依据传统耕作的最晚栽培时间,将作物生长季节划分为两个时期,在第1个时期里所有耕作处理小区的土壤流失量,占总土壤流失量85%以上.在播种阶段,传统耕作小区产生径流最大,而在其它所有生长阶段,少耕无覆盖小区产生的径流最大.在高强度降雨条件下,两种少耕法比传统耕作产生更大的径流量.少耕有覆盖、少耕无覆盖及传统耕作试验小区,3年平均籽棉产量分别为2223,2123,2076kg/ha.由于耕作方法不同,籽棉产量也不同.在干旱年景,水土保持耕作法的经济效益明显超过传统耕作法.1987年在作物种植前和临界生长期,因为连续两次干旱,使少耕有覆盖小区出现了严重减产现象.
In Tennessee, Alabama Basin, three cropping practices for cotton growth were studied in a plot of surface runoff and soil loss caused by natural rainfall, with the largest amount of soil loss being the result of conventional farming practices, followed by less According to the latest cultivation time of traditional farming, the crop growth season is divided into two periods, in the first period of soil erosion in all tillage communities, Accounting for more than 85% of the total soil loss. In the sowing stage, the traditional farming plot had the largest runoff, while in all other growth stages, the runoff in the no-tillage and uncultivated plot was the largest. Under high rainfall intensity, The traditional tillage produced more runoff.With less tillage, less tillage and no-tillage and traditional tillage plot, the average seed cotton yield in three years was 2223,2123 and 2076kg / ha, respectively.The yield of seed and cotton was also different due to the tillage method. Drought years, the economic benefits of soil and water conservation farming method significantly more than the traditional farming method 1987 before crop planting and critical growth period, because of two consecutive droughts, so that less tillage with coverage of the community out The severe cuts phenomenon.