摘要
在大田已连续少耕３季的基础上，分区设定“２年４熟”一个轮耕周期的土壤耕法组合定位试验，对试验第４季的小麦进行了较系统的测定。结果表明：①轮耕后耕层土壤容重和穿透阻力居于连少和连耕之间，保持在小麦生长的适宜范围内，利于土壤供肥能力的提高和小麦根系的生长发育。②肥料和耕法对小麦含氮率和累积吸氮量均有影响，成熟期各耕法不施肥区茎秆和籽粒含氮率分别占施肥区的２／３和３／４左右，而累积吸氮量仅为施肥区的１／３；不同耕法中，无论施肥或不施肥均以轮耕为最高，施肥区籽粒含氮率和累积吸氮量分别比连少高１０．８％和３４．６％。③小麦产量以轮耕为最高，比连耕、连少增产２．７％～３４．２％；不同耕法不施肥区产量占施肥区产量比例不同，连少、连耕、轮耕分别约为４０％、４５％和５０％。可以认为在地力较差或施肥水平较低的地方更应避免长期连续少耕。
This study was carried out on the field with continuous minimum tillage for 3 growing seasons. A group of experiments was arranged on a fixed position within a rotation tillage cycle with 4 growing seasons in 2 years,and the wheat plant in the 4th growing season was measured systematically. Results showed as following: ① The bulk density and penetration resistance of the soil treated with rotation tillage (RT) lay between that of the soil treated with continuous minimum tillage (CMT) and conventional tillage (CCT) and was suitable to enhance the supply of soil nitrogen and development of wheat roots. ② Nitrogen contents of wheat stalk and seed at maturing stage without application of nitrogen occupied 2/3 and 3/4 of that with nitrogen application respectively, while total amount of nitrogen accumulated by the plant occupied only 1/3. Nitrogen accumulation of wheat plant treated with RT ranged highest among different tillage methods regardless of nitrogen application. Nitrogen content of seed and accumulation of plant with RT increased 10 8% and 34 6% respectively over that with CMT applied with nitrogen. ③ The yield of wheat with RT increased 2 7%￣34 2% compared with that with CMT and CCT. The proportion of the yield without application of nitrogen application to that applied with nitrogen varied with tillage methods, which was 40%, 45% and 50% for CMT, CCT and RT respectively. Therefore, avoiding long term continuous minimum tillage was more important in soils with low levels of soil fertility and fertilizer application.
出处
《江苏农学院学报》
CSCD
1998年第2期49-52,共4页
Jiangsu Agricultural Research
基金
国家自然科学基金
关键词
耕作
小麦
土壤肥力
氮素吸收
soil cultivation
wheat
soil fertility
nitrogen nutrition
