Bioactivity of humic substances extracted from soils managed with integration, agriculture, livestock and forestry

ABSTRACT The humified organic matter promotes biostimulating effect such as auxins. However, information is needed on plant stimulation capacity of humic substances from soils managed with systems integrating crops, livestock, and forests. The aim of this study was to evaluate the initial performance of maize in response to the application of increasing concentrations of isolated humic substances from soils managed with integrated system of crop, livestock, and forests, applied at seed, comparing them also with humic substances isolated from soil with eucalyptus and isolated pasture and with a Cerrado adjacent area. The corn seeds were treated for 16 hours in solutions containing 0, 10, 20, 30, 40, and 80 mmol L-1 of C from humic substances. Then, the seeds were planted in pots of 1 dm3 containing corrected and fertilized soils, in greenhouse. Growth characteristics of shoot and root systems were evaluated. The results showed that the humic substances extracted from soils with integration of crop, livestock, and forests have positive effects on the initial performance of corn, superior to those observed under control (133%), Cerrado (29%), eucalyptus (30%), and isolated pasture (56%).

摘要 腐殖化有机质可发挥类似生长素的生物刺激效应。然而，针对农林牧综合管理模式下土壤中腐殖物质的植物刺激能力，现有研究信息仍存在不足。本研究旨在评估以种子处理方式施加不同浓度的农林牧综合管理土壤提取腐殖物质时，玉米的初始生长表现，并将其与桉树种植土壤、天然牧草地土壤以及邻近塞拉多（Cerrado）区域土壤提取的腐殖物质进行对比。实验将玉米种子置于含0、10、20、30、40、80 mmol·L⁻¹碳浓度的腐殖物质溶液中浸种16小时，随后播种于容积1 dm³的盆钵中，盆钵内为经过理化校正与施肥处理的土壤，栽培环境为温室。随后测定植株地上部与根系的生长性状。结果表明，从农林牧综合管理土壤中提取的腐殖物质可显著促进玉米初始生长，其促生效果较对照组提升133%，较塞拉多（Cerrado）区域土壤腐殖物质组提升29%、桉树种植土壤腐殖物质组提升30%以及天然牧草地土壤腐殖物质组提升56%。