不同保水措施对砂质潮土水分、微生物量及小麦产量的影响

Effects of water conservation measures on soil moisture, microbial biomass and wheat yield in a sandy fluvio-aquatic soil

通过研究不同保水措施对砂质潮土的保水效应、微生物量及小麦产量的影响,为中低产田砂质潮土的土壤改良及小麦产量提升提供科学依据。在黄淮海平原麦-玉轮作的典型砂质潮土区,设置常规耕作无保水措施的对照(T)、秸秆还田(TS)、生物炭还田(TB)、秸秆与生物炭配合还田(TS+B)和秸秆与保水剂配合还田(TS+W)5种田间保水措施。结果表明,与T相比,4种保水措施均显著提高了分蘖期土壤含水量,其中TS+W含水量最高,0~20 cm土层增加21.9%,20~40 cm土层增加69.4%,随着生育期延长,保水效果逐渐降低;与之相反,TS+B处理显著提高小麦生育后期的土壤含水量,在灌浆期提高18.8%,成熟期提高32.6%。在小麦分蘖期,0~20 cm土层各处理间微生物量碳无显著差异,与T相比,TS、TB和TS+W处理显著提高20~40 cm土层中土壤微生物量碳,分蘖期增幅最大的是TS,提高量为212.7%,灌浆期增量最大的是TS+W,提高31.6%。各处理小麦产量均有所增加,其中TS+W产量提升31.4%,其中仅TS+W与T处理达到差异显著水平。土壤水分与小麦产量性状、微生物量碳含量的相关分析发现,土壤水分含量是砂质潮土生产力低下的主要限制因素,主要在小麦分蘖期和拔节期影响小麦产量。4种保水措施均不同程度改善砂质潮土的理化性质,增加土壤含水量、微生物量和作物产量,其中秸秆和保水剂配合施用对砂质潮土小麦增产效果最佳。

In order to explore the effects of different methods of water conservation on the water holding capacity of sandy fluvio-aquatic soil,soil microbial biomass and wheat yield,a field experiment was carried out for providing scientific and rational basis for the soil improvement in the Yellow-Huaihai plain wheat-maize rotation of the typical sandy soil area.In this study,5 field treatments were designed,including the treatment without water conservation measures(T)as control,straw returning(TS),biochar application(TB),combined straw and biochar(TS+B)and combined straw and water retaining agent(TS+W). Soil moisture,microbial biomass carbon,soluble carbon and crop yield were compared and analyzed in different wheat growing stages. Results showed that: compared with T,4 water conservation treatments significantly increased soil water content in wheat tillering stage,and TS+W showed the highest water moisture,increased by21.9% and 69.4% in 0 ~ 20 cm and 20 ~ 40 cm soil layer,respectively. On the contrary,TS+B significantly increased soil moisture in the later wheat growing stage,increased by 18.8% and 32.6% in filling stage and ripening stage,respectively.There were no significant difference of microbial carbon content among all treatment in tillering stage in 0 ~ 20 cm soil layer,while compared with T, TS, TB and TS+W significantly increased soil microbial carbon in 20 ~ 40 cm soil layer, TS treatment increased by 212.7% in tillering stage and TS+W treatment increased by 31.6% in filling stage, respectively, and TS+B significantly increased soil microbial carbon in 0~20 cm soil layer. All the four water conservation measures increased wheat yield in some extent. However,only TS+W showed significant difference which increased by 31.4%. Correlations between soil moisture and microbial carbon or wheat yield indicated that water was a key factor for the productivity of sandy soils,and tillering stage was more sensitive. The four water conservation methods could increase soil water content,microbial biomass and wheat yield in some extent,and the method of combined wheat and water retaining agent was the best in all,and the yield were increased obviously.