Effects of planting patterns plastic film mulching on soil temperature,moisture, functional bacteria and yield of winter wheat in the Loess Plateau of China

The yield of winter wheat is hindered by drought and low temperature in the Loess Plateau of China.Two common mulching methods to conserve soil moisture,ridge furrows with plastic film mulching (RP) and flat soil surfaces with plastic film mulching (FP) are helpful for wheat production.Our previous study indicated that FP could improve wheat yield more effectively than RP,but the reason remains unclear.The effect of mulching method on functional bacteria also needs to be further studied.In this study,winter wheat was employed to evaluate the impacts of mulching method on soil temperature,moisture content,microorganisms and grain yield.The results showed that FP had a warming effect when the soil temperature was low and a cooling effect when the temperature was too high.However,the ability to regulate soil temperature in the RP method was unstable and varied with year.The lowest negative accumulated soil temperature was found in the FP treatment,which was 20–89 and 43–99%lower than that of the RP and flat sowing with non-film mulching control (NP) treatments,respectively.Deep soil moisture was better transferred to topsoil for wheat growth in the FP and RP treatments than the NP treatment,which made the topsoil moisture in the two treatments (especially FP) more sufficient than that in the NP treatment during the early growing stage of wheat.However,due to the limited water resources in the study area,there was almost no difference between treatments in topsoil water storage during the later stage.The wheat yield in the FP treatment was significantly higher,by 12–16and 23–56%,respectively,than in the RP and NP treatments.Significant positive correlations were observed among the negative accumulated soil temperature,spike number and wheat yield.The Chao1 and Shannon indices in the RP treatment were 17 and 3.9%higher than those in the NP treatment,respectively.However,according to network relationship analysis,the interspecific relationships of bacteria were weakened in the RP treatment.Phosphorus solubilizing,ammonification and nitrification bacteria were more active in the RP than in the FP treatment,and microbes with nitrate reduction ability and plant pathogens were inhibited in the RP treatment,which improved nutrient availability and habitat for wheat.

有机-无机复合保水材料对旱地麦田土壤水分及酶活性的影响

通过大田试验,研究了有机-无机复合保水材料对旱地麦田土壤水分及酶活性的影响,以期为有机-无机复合保水材料的研究和应用提供一定的理论依据。结果表明,有机-无机复合保水材料能在短期内明显提高土壤含水量,在0~20 cm土层较对照提高8.46%(p≤0.05),在20~40 cm土层较对照提高6.15%(p≤0.05)。与对照相比,有机-无机复合保水材料能显著提高土壤过氧化氢酶、蔗糖酶、脲酶和碱性磷酸酶的活性,且不同处理0~20 cm土层的土壤酶活性均高于20~40 cm土层。在0~20 cm土层,不同处理土壤含水量与土壤酶活性均呈显著正相关(p≤0.05);在20~40 cm土层,土壤含水量与土壤过氧化氢酶活性呈显著正相关(p≤0.05),而土壤含水量与蔗糖酶、脲酶、碱性磷酸酶活性相关性不显著。

有机肥替代化肥比例对黄壤土活性有机碳及酶活性的影响

为明确等量养分施肥条件下,有机肥替代化肥不同比例对黄壤土活性有机碳及土壤酶活性的影响,以贵州省典型的黄壤土为对象,研究不施肥(CK),单施化肥(T1),70%化肥+30%有机肥(T2),50%化肥+50%有机肥(T3),30%化肥+70%有机肥(T4)和单施有机肥(T5)对土壤总有机碳(TOC)、溶解性有机碳(DOC)、易氧化性有机碳(ROC)、微生物生物量碳(MBC)含量和土壤纤维素酶、蔗糖酶、脲酶、酸性磷酸酶活性及辣椒产量的影响。结果表明:有机肥替代化肥能显著提高土壤总有机碳和各组分土壤活性有机碳含量,土壤TOC、DOC、ROC和MBC含量较单施化肥处理分别提高15.45%~55.82%、20.29%~91.30%、34.85%~51.21%和37.78%~71.11%;土壤有机碳库管理指数(CMI)较单施化肥处理提高36.95%~53.78%;随着有机肥替代化肥比例的增加,土壤纤维素酶、蔗糖酶和脲酶活性均呈现出先增加后降低的趋势,土壤酸性磷酸酶活性则呈现出不断提高的趋势;与不施肥对照相比,施肥明显提高了辣椒产量,50%化肥+50%有机肥处理的辣椒产量达到25 765.63 kg·hm^(-2),较其他施肥处理显著提高13.90%~49.36%。整体来看,有机肥替代化肥有助于提升黄壤土活性有机碳含量、土壤有机碳库管理指数、微生物活性及辣椒产量。从提高土壤固碳角度和增产效应出发,50%化肥+50%有机肥施用比例为推荐施肥措施。