大豆适宜耕深在一尺以內,产量随耕层加深而递增,增产幅度在10—20％左右;根密层伸入土层深度及吸肥最强的根系部位,都是在20或30厘米土层以內;土壤理化生物特性的变化,以及微生物活动性及养分轉化的速度,亦以20—25厘米为最大。因此,加深土壤耕层以20一30厘米为限,在現有农具机耕条件下,以18—25厘米为宜。 Soybean suitable for deep plowing within a foot, the yield increased with the deepening of the tillering, yield increase of about 10-20%; root depth into the depth of the soil and fat absorption of the strongest roots, are 20 or 30 cm Soil layer; changes in soil physical and chemical biological characteristics, and microbial activity and nutrient conversion rate, but also to 20-25 cm maximum. Therefore, to deepen the soil plow to 20-30 cm limit, in the existing farm machinery plowing conditions, to 18-25 cm is appropriate.