稻田少耕轮耕体系及其配套机具的研究(Ⅲ)——稻田少耕轮耕体系与水稻生育

稻田少耕轮耕体系研究,进行了两种耕作方法及其轮耕体系试验。第Ⅰ、Ⅱ报报道了这一体系的设计指导思想及其实测的经济效益和这一耕作体系对稻田土壤物理性状的影响。本文则重点论述这一耕作体系对水稻生育和产量的影响。深翻深松和浅翻深松将耕作层由16厘米加深到21—29厘米,对水稻地上部及根系有良好的影响,并比对照区分别增产19.6％和11.9％。深翻深松的后效增产14.9％。由此肯定了稻田加深耕作层的必要性。但深翻深松的作业成本高于一般翻地,而且有推迟成熟的趋势。稻田间隔深松的耕作层加深至27厘米。由于它使肥沃土层位置不变,底土在原处熟化和控制适宜的透水性,导致水稻增产显著。其中间隔35厘米深松比翻地增产12.8％,而间隔70厘米深松增产不明显。间隔35厘米深松与耙茬轮耕后增产12.6％,作业成本比翻地降低50％以上。由此肯定了稻田间隔深松的少耕轮耕体系,并为研制水旱兼用的旋耕深松机提供了设计根据。

SYSTEM OF LESS AND ALTERNATE TILLAGE OF PADDY FIELD AND COMPLETE SET OF IMPLEMENT

Deepening the tilth of paddy field of meadow soil from 16 cm to 25—27cm will disturb the plow-pan and improve the soil environment for rice growth. The increase of the quantity of shoot and root growth can increase the rice yield significantly. Deepening the tilth of paddy field has "subsequent effect" at least, in the following year. It lays a foundation for the neccessity of deepening the tilth and for the possibility to set up the system of less tillage and alternative tillage of paddy field. The interval subsoiling 35 cm apart and then disking the next year have greater economical effect than upper plowing and lower subsoiling. For example, the interval subsoiling 35 cm apart tillage system will not only reduce the cost but save energy as well, it can keep the surface soil leveling, it will conserve the fertility of low soil layer and will be utilized more economically. There would be more efficiency if the lands were leveled before subsoiling. These experiments provide a basis of design and mauufacture for the interval subsoiling of paddy field implement roto-subsoiler.