To further clarify the mechanism of advantage effects of straw mulching,a field experiment was carried out to study the effects of seven straw mulching patterns,i.e. M0 (0 kg·hm-2),M1 (4 000 kg·hm-2,with interlacing mulched),M2 (4 000 kg·hm-2,with each row mulched ),M3 (8 000 kg·hm-2,with interlacing mulched),M4 (8 000 kg·hm-2,with each row mulched),M5 (12 000 kg·hm-2,with interlacing was mulched) and M6 (12 000 kg·hm-2,with each row mulched) on wheat. The results showed that properly increasing straw mulching quantity could help to enhance the internode length and plant height of wheat,and under the same straw mulching quantity,the internode length and plant height of the treatment with each row mulched were higher than those of treatment with interlacing mulched,and the differences in plant height between M2 and M1,M5 and M6 were significant. The dry matter weight per stem of M2,M3,M4,M5,and M6 were significantly higher than that of M0 at booting stage and middle of filling stage. Compared to the treatment without straw mulching,properly straw mulching quantity can significantly increase flag leaf length,width and leaf area,and under the same straw mulching quantity,the difference in flag leaf length and width between treatments of each row mulched and interlacing mulched was not significant,but the difference in flag leaf area was significant at middle of filling stage. Straw mulching compared to the treatment without straw mulching,and under the same straw mulching quantity,treatment of each row mulched compared to the treatment of interlacing mulched could increase chlorophyll fluorescence parameters of Fm,Fv/Fm,ΦPSII and ETR,and decrease Fo. The treatment of M4 has the highest values of photosynthetic rate,stomatal conductance and transpiration rate. Compared to M0,the values of M4 were increased by 25.5%,45.6% and 26.4%,respectively,and the treatment of each row mulched was more conducive to improve photosynthesis,compared to the treatment of interlacing mulched under the same straw mulching quantity. The yield of M0 was the lowest (7 846.00 kg·hm-2),and of M4 was the highest (8 408.03 kg·hm-2). Under the same straw mulching quantity,the yield of M2,M4 and M6 were increased by 1.6%,1.4% and 1.2%compared to M1,M3,and M5,respectively. Dry matter weight per stem,flag leaf area,actual photochemical efficiency,and photosynthetic rate of wheat were significantly positively correlated to yield with the shape of a straight line. The studies show that straw mulching quantity is too high or too low and interlacing mulched are not conducive to improve plant traits,photosynthesis and yield of wheat,and each row mulched with the quantity of 8 000 kg·hm-2 is the suitable straw mulching model for Huaibei Area in Anhui province. |