不同耕作方式及施氮水平对砂姜黑土物理性状、微生物学特性及小麦产量的影响

Effect of Different Tillage Methods and Nitrogen Application Amount on Lime Concretion Black Soil Physical,Microbial Characteristics and Wheat Yield

在玉米秸秆还田条件下,以矮抗58为材料,探讨旋耕高氮(RT+HN)、旋耕中氮(RT+MN)、旋耕低氮(RT+LN)、深耕高氮(DT+HN)、深耕中氮(DT+MN)、深耕低氮(DT+LN)6个处理对砂姜黑土物理性状、微生物学特性及小麦产量的影响,以期探明砂姜黑土农田适宜的耕作和施氮组合并为土壤改良提供理论依据。结果表明,从耕作方式来看,与旋耕处理相比,深耕处理可显著降低15~35 cm土层土壤的容重,深耕处理15~25 cm和25~35 cm土层土壤容重分别降低5.9%和7.7%;可显著提高苗期15~35 cm土层土壤含水量;可提高15~25 cm土层土壤微生物生物量碳含量,显著提高15~25 cm土层土壤微生物生物量氮含量;可显著提高土壤酶活性;可显著提高穗粒数和千粒质量,2 a分别增产7.5%和7.7%。从施氮水平来看,施氮水平对土壤容重和土壤含水量影响不显著,氮肥能够抑制土壤微生物生物量碳含量,促进土壤微生物生物量氮含量增加;与中氮和低氮处理相比,2 a高氮处理分别增产2.3%、2.6%和7.2%、6.9%。从不同处理来看,DT+HN/MN处理对降低土壤容重、提高土壤含水量和土壤微生物生物量氮含量效果较好,对增强土壤脲酶和过氧化氢酶活性效果较好;小麦产量以DT+HN处理最高,DT+MN处理次之,两者差异不显著,RT+LN处理最低,DT+HN处理分别较DT+MN和RT+LN处理增产2.7%和14.7%。综合考虑,DT+MN处理最佳。

Under the condition of returning corn stalks to field, this paper was carried out to investigate the effects of different tillage methods [ rotary tillage （ RT） , deep tillage （ DT） ] and nitrogen application tion black soil physical properties,microbiological characteristics and wheat yield, with wheat cultivar Ai- kang 58 as the material. The results showed that compared with RT treatment, soil bulk density of DT treatment significantly decreased in 15 -35 cm soil layer, and decreased by 5. 9% and 7.7% in 15- 25 cm and 25 -35 cm soil layer respectively; soil water content of DT treatment significantly improved in 15-35 cm soil layer at seedling stage; soil microbial biomass carbon（ SMB-C ） content of DT treatment increased in 15 -25 cm soil layer, soil microbial biomass nitrogen （ SMB-N） content of DT treatment in-creased significantly in 15-25 cm soil layer; activity of soil enzyme of DT treatment significantly in -creased; grains per spike and 1000-grain weight of DT treatment significantly increased and hence grain yield increased by 7. 5% and 7.7% in two years. The nitrogen application amount had no significant in-fluence on soil bulk density and water content ,nitrogen could inhibite SMB-C content ,promote the SMB- N content. Compared with MN and LN treatments,yield of HN treatment increased by 2. 3%,2. 6% and 7.2%,6. 9% in two years. Compared with different treatments, DT ＋ HN/MN treatments did well in de-creasing soil bulk density, increasing soil water content and SMB-N content, enhancing both soil urease and catalase activities. The yield of DT ＋ HN treatment was the highest, and DT ＋ MN treatment was the second. There was no significant difference between the two treatments. RT ＋ LN treatment was the lowest.Compared with DT ＋ MN and RT ＋ LN treatments, wheat yield of DT ＋ HN treatment increased by 2. 7% and 14. 7% respectively. In summary, DT ＋ MN treatment was the best.