干旱区生态环境知识资源中心

In order to explore the characteristics and relationship between soil temperature and yield of winter wheat, under different sowing quantities conditions of straw mulching conventional drilling in Northwest China, this study took Lantian 26 as material, under the whole corn mulching conventional drilling in Changhe town and Pingxiang town, setting up 3 different seeding quantities of 270 kg/ha (SSMC1), 324 kg/ha (SSMC2) and 405 kg/ha (SSMC3), to study the difference of soil temperature during the growth period of winter wheat and its correlation with yield components. Results showed: the average soil temperature of 0-25cm in two ecological zones in the whole growth period have a significant change with the increase of sowing quantities; too much seeding had a sharp drop in soil temperature; the highest temperature of SSMC in Changhe town was the middle quantity of SSMC 2; the highest temperature of SSMC in Pingxiang town was the lowest sowing quantity of SSMC1. Diurnal variation of soil temperature at all growth stages showed: with the increase of SSMC, in the morning it increased with the increase of soil depth, noon and evening reducing with the depth of the soil. The average soil temperature of SSMC2 was higher than that of in all the two ecological zones in the whole growth period of SSMC.The maximum day temperature difference of each treatment was at noon. With the increase of SSMC, the yield increase varied with two ecological zones. SSMC of the local conventional sowing quantity of 270kg/ha SSMC1 yield was the highest in Changhe Town. SSMC of the middle sowing quantity SSMC2 of 324kg/ha yield was the highest in Pingxiang town. The difference of grain number per spike was the main cause of yield difference among these 3 treatments. Correlation analysis showed: the correlation among the yield and yield components, growth index and soil temperature varied with different ecological zones; thousand kernel weight and grain number per ear (.964** and.891**) had a very significant positive correlation with the yields in Changhe Town, but thousand kernel weight and grain number per ear (.708* and.718*) had a significant positive correlation with yield in Pingxiang Town. There was a significant positive correlation between harvest index and 10cm soil temperature (.763*). But in Pingxiang Town grain number per ear and 15cm soil temperature showed a significant positive correlation (.671*); 15cm soil temperature and the average temperature of 0 similar to 25cm soil layer in the whole growth period (-.687* and -.698*) had a significant negative correlation with the number of panicles per unit area; there was a very significant negative correlation between plant height and average temperature of 0-25cm in the whole growth period (-.906**). Thus, the changes of soil temperature under SSMC different sowing quantity have indirect effect on the yield of winter wheat.