【摘要】 甘肃砂田在战胜干旱与保证作物高额而稳定的产量方面具有特殊功效。但是它也具有寿命短促与机械化困难等两个严重的缺点。这两个缺点产生的基本原因在于耕作过程中砂石容易和土壤混合之故。为了改进这种缺点,我们提出用直径5毫米以上的砾石来代替砂石混合物作为土壤覆盖层。根据三年来的试验结果,证明:(1)纯砾石层覆盖下的土壤温度并不低于砂石混合层(见表1);(2)纯砾石层的保存土壤水分的作用大于砂石混合层,这主要由于在纯砾石层覆盖之下,土壤水分的蒸发率小,而雨水的渗漏速度大之故(见表2和表3);(3)利用纯砾石层代替砂石混合层对于作物的生长与产量并无不利的影响。对于利用这种改良方法能够延长砂田使用年限与进行机械化耕作的可能性也加以讨论。更多还原

【Abstract】 Experiments were conducted in 1955—1957 to determine the merits of the use of gravel as a soil mulch material instead of a mixture of sand and gravel widely used in Kansu.The results showed that(1)the effect of the gravel mulch on the soil temperature was as favorable as that of the sand-gravel mulch,(2) the gravel mulch was more effective in retaining soil moisture and(3)the growth and yield of the wheat grown on gravel mulched soil were slightly higher than those on sand-gravel mulched soil. The possibility of lengthening the effective period of the gravel mulch and of operating of farm machineries in gravel mulched fields is discussed.更多还原