不同耕作条件下春小麦干物质积累动态及其相关性状的研究

为了给干旱区春小麦耕作模式的选择提供依据,通过田间试验,研究了传统耕作(CT)、秸秆还田(CS)、免耕不覆盖(NT)和免耕覆盖(NTS)四种耕作模式对干旱区春小麦各器官干物质积累动态及产量的影响.结果表明,四种模式下小麦地上部干物质的累积量随生育时期均呈"S"型曲线增长,均在开化后30 d达最大值,且在CS、NT和NTS处理下总干重最大值分别比传统耕作(CT)高15.40%、24.58%和35.17%,差异达到显著水平.其中,在整个籽粒形成期内总干物质增加速度表现为NTS＞NT＞CS＞CT;与传统耕作(CT)相比,CS、NT和NTS的籽粒干物质积累速度分别提高了14.68%、31.57%和45.92%.处理NTS的产量及其相关性状均优于其他处理.进一步分析表明,NTS产量提高的原因是由于光合产物在各器官中的分配比例发生变化,收获指数增加,使籽粒所占的百分率得以提高.另外,免耕覆盖能增大春小麦籽粒灌浆速度,延长灌浆时间,有利于光合产物的合成和花后同化物向籽粒的转运.

Dynamics Change of Dry Matter Accumulation and Relative Characteristics of Spring Wheat under Different Tillage

In order to improve the grain yield of spring wheat in arid areas,field experiments were carried out on the Xinjiang Uygur Autonomous Region.The effects of four different tillage treatments on wheat dry matter accumulation of each organ and grain yield were studied.The four different tillage treatments were conventional tillage(CT),conventional tillage with straw mulching(CS),no-till with no straw mulching(NT) and no-till with straw mulching(NTS).The major results showed that the change of total dry matter accumulation of Xinchun 6 was consistent with the typical "S" curve.The four different tillage treatments all reached maximum values at 30 d after anthesis.Compared with conventional tillage(CT),the maximum dry matter accumulation amounts of CS,NT and NTS treatments were increased by 15.40%,24.58% and 35.17%,respectively.The effect of different treatments on total ADM increasing rate was in the following order:NTS>NT>CS>CT.The treatments of CS,NT and NTS could improve the growth of spring wheat and were responsible for improvement of their yield,with increasing 14.68%,31.57% and 45.92% respectively compared with the convention tillage.No significant differences were found between the treatments of NT and NTS,but there were significant differences among other treatments.Overall,the results showed that the comprehensive characters were most superior by the treatment of NTS.The rates of dry matter distribution among different organs of spring wheat were changed and harvest index was enhanced.Therefore,the ratio of the grain yield to biomass was higher than the others.At the same time,no-till with straw mulching(NTS) could enlarge the grain filling rate and extend the duration of grain filling,which was enhancing the transportation of the photosynthate after anthesis.