不同施肥措施对旱地采煤塌陷区复垦土壤结构及玉米品质的影响

研究不同施肥措施对复垦土壤结构及玉米品质的影响,以期深入理解采煤塌陷区复垦土壤有机碳固持机制。采集复垦1年的定位试验各处理耕层(0—20 cm)土样以及玉米籽粒,分析土壤水稳性团聚体(>2,0.25~2,0.053~0.25 mm)及粉黏粒组分(<0.053 mm)中有机碳(SOC)及全氮(TN)含量、玉米籽粒蛋白质、淀粉和脂肪含量的变化。试验设不施肥(CK)、施化肥(NPK)、单施有机肥(M)和有机无机肥配施(MNPK)4个处理。结果表明,同CK相比,NPK处理显著提高TN含量、玉米籽粒产量、淀粉和脂肪含量,增幅分别为11.23%,98.53%,1.16%和12.71%;M处理显著提高SOC、TN、>2 mm和0.25~2 mm团聚体中有机碳含量、籽粒产量、蛋白质、淀粉和脂肪含量,增幅分别为44.77%,13.23%,52.73%,60.22%,255.15%,23.28%,1.67%和12.71%;MNPK处理显著提高SOC、TN、各粒径团聚体及粉黏粒组分中SOC和TN含量(除0.25~2 mm团聚体中TN含量)、玉米籽粒产量、蛋白质、淀粉和脂肪含量,增幅分别为46.21%,29.08%,39.23%(>2 mm-C),49.07%(0.25~2 mm-C),110.41%(0.053~0.25 mm-C),40.35%(<0.053 mm-C),22.48%(>2 mm-N),43.29%(0.053~0.25 mm-N),33.33%(<0.053 mm-N),211.37%,35.34%,0.48%和25.18%。表明当养分投入量相同时,有机无机肥配施(MNPK)有利于采煤塌陷区复垦土壤团聚体对有机碳的物理保护,增加土壤有机碳累积,提升土壤肥力,提高作物产量,改善作物品质。

Effects of Different Fertilization Regimes on Reclaimed Soil Structure and Maize Quality in Dryland

To better understand the mechanism of soil organic carbon(SOC)sequestration in the reclaimed coal-mining subsiding region,we investigated the response of the structure of reclaimed soil and maize quality.Top soil samples(0—20 cm)and maize grain were collected from different treatments of a 1-year reclaimed field,and the wet sieving method was used to analyze the changes of soil organic carbon and total nitrogen(TN)contents within water-stable aggregates and silt and clay fractions,and grain analyzer was used to analyze protein,starch and fat contents in maize grain.The experiment was set up with four treatments:no fertilizer(CK),chemical fertilizer(NPK),organic fertilizer(M)and combined application of organic and inorganic fertilizer(MNPK).The results showed that compared with CK,NPK treatment significantly increased TN content,maize grain yield,starch and fat content by 11.23%,98.53%,1.16%and 12.71%respectively.The M treatment significantly increased SOC,TN,the organic carbon contents,grain yield,protein,starch and fat contents in>2 mm and 0.25~2 mm aggregates by 44.77%,13.23%,52.73%,60.22%,255.15%,23.28%,1.67%and 12.71%,respectively.The MNPK treatment significantly increased SOC,TN,SOC and TN contents in aggregates of various particle sizes and powder clay components(except for total nitrogen content in 0.25~2 mm aggregates),maize grain yield,protein,starch and fat contents.The increase was 46.21%,29.08%,39.23%(>2 mm-C),49.07%(0.25~2 mm-C),110.41%(0.053~0.25 mm-C),40.35%(<0.053 mm-C)),22.48%(>2 mm-N),43.29%(0.053~0.25 mm-N),33.33%(<0.053 mm-N),211.37%,35.34%,0.48%and 25.18%,respectively.This study shows that when the nutrient input is the same,the combined application of organic and inorganic fertilizers(MNPK)is beneficial to the physical protection of organic carbon by reclaimed soil aggregates in the coal mining subsidence area,increasing SOC accumulation,improving soil fertility,and increasing crop yields and quality.