微生物改良剂动态施用对盐碱地春玉米生长及产量的影响

Microbial inoculants improve growth and yield of spring maize in saline-alkali soil

【目的】利用微生物改良盐碱地具有绿色高效的特点,是实现盐碱地综合改造利用和耕地质量提升的重要措施之一,本文旨在研究盐碱地综合治理时微生物改良剂的合理施用方法。【方法】于2022年研究获得了未进行盐碱地改良时影响春玉米生长的耐盐阈值,2023年在修建排水沟、施用有机肥和采用滴灌进行盐碱地综合改良的基础上,以不施用微生物改良剂的处理为对照,研究了中度盐碱地基施600 kg/hm^(2)固态微生物改良剂、基施300 kg/hm^(2)固态微生物改良剂和在拔节期与抽穗期各追施75 L/hm^(2)液态微生物改良剂、基施300 kg/hm^(2)固态微生物改良剂和根据耐盐阈值进行每次75 L/hm^(2)液态微生物改良剂动态追施的微生物改良剂施用方法对玉米生长和产量的影响。【结果】在苗期、拔节期、抽穗期和灌浆期影响春玉米生长的耐盐阈值分别为1.77、2.28、5.07、5.27 g/kg。与未进行盐碱地改良的2022年玉米相比,进行改良后的各处理玉米出苗率和产量均显著提高,出苗率由34.4%最大提高到70.1%,产量由4.20 t/hm^(2)最大提高到8.62 t/hm^(2),平均增产88.0%。在不同微生物改良剂施用方法的处理下,各处理的株高、叶面积指数、地上部分干物质量和叶片相对叶绿素量在峰值时期分别较对照处理提高了9.9%~17.1%、38.4%~56.1%、26.7%~32.0%和9.2%~11.2%,产量较对照处理提高了30.6%~36.0%,其中基施固态微生物改良剂和根据耐盐阈值进行液态微生物改良剂动态追施的处理对春玉米出苗率、生长指标和产量的提高幅度最大。【结论】在采用排水沟+有机肥+微生物改良剂进行春玉米盐碱地综合治理时,建议微生物改良剂的施用方法宜采用固态基施(300 kg/hm^(2))和液态追施(150 L/hm^(2))相结合,且追施时间宜根据耐盐阈值进行动态调整。

【Background and Objective】Saline-alkali soil is characterized by excessive salt and alkali content,poor physical and chemical properties.Efficient utilization,improvement and development of saline-alkali soil resources is important for food security.Microbial amendments are a green and efficient method for improving saline-alkali soil.This study is to explore the efficiency of microbial inoculants in improving the properties and productivity of saline-alkali soils.【Method】Salt-tolerance critical contents in different growing stages of spring corn in the saline-alkali soils were obtained first in 2022 before soil amendment.In 2023,the saline-alkali soil was amended by building drainage ditch,organic fertilization and drip irrigation.The soils were further amended by microbial inoculants applied in different ways:i)applying 600 kg/hm^(2) of solid microbial amendments as base,ii)applying 300 kg/hm^(2) of solid microbial amendment as base coupled with applying 75 L/hm^(2) of liquid microbial inoculants at the jointing stage and the heading stage,respectively,iii)applying 300 kg/hm^(2) of basal solid microbial amendment coupled with applying 75 L/hm^(2) of liquid microbial inoculant dynamically based on the critical salt tolerance contents measured in 2022.The control was soil without microbial amendment.【Result】The salt tolerance critical content at the seedling stage,jointing stage,heading stage and filling stage were 1.77,2.28,5.07 g/kg and 5.27 g/kg,respectively.Compared to 2022,amending the soil in 2023 increased seedling emergence rate by 34.4%to 70.1%,and grain yield by 4.20 t/hm^(2) to 8.62 t/hm^(2).Compared to the control,microbial amendment increased plant height,leaf area index,above-ground dry matter mass and relative chlorophyll content of the leaves by 9.9%-17.1%,38.4%-56.1%,26.7%-32.0%and 9.2%-11.2%,respectively,and grain yield by 30.6%-36.0%.Dynamically applying microbial amendment based on soil salt content significantly increased the seedling emergence rate,growth index and grain yield.【Conclusion】Our results show that combining drainage ditches,organic fertilization and microbial amendments can substantially improve productivity of the saline-alkali soil for spring corn.Specifically,applying 300 kg/hm^(2) of solid amendments as base coupled with dynamically applying 150 L/hm^(2) of liquid microbial inoculants based on salt tolerance critical content was most effective to improve productivity of the soil.