Abstract

The addition of carbonaceous material such as cow bonechar to the soil can affect the availability of applied pre-emergent herbicides such as indaziflam. However, how cow bonechar affects the bioavailability of indaziflam is not yet known. The aim of this study was to evaluate the effect of cow bonechar on herbicidal activity of indaziflam on weeds in a tropical soil. Cow bonechar was added homogeneously to top soil, at 1, 2, 5, 10, and 20 t ha⁻¹, in addition to treatment with unamended soil. At 21 days after indaziflam (75 g ha⁻¹) application, injury weed levels, weed species that emerged spontaneously were identified and the weeds present in each sampling unit were collected. Only 1.4 t ha⁻¹ cow bonechar added to soil was enough to reduce the weed injury level by 50%. From the addition of 2 t ha⁻¹ cow bonechar the application of indaziflam was not efficient to weed control, being equivalent to treatments without herbicide application. Eight weed species (3 monocots and 5 dicots) were identified in all treatments. Eleusine indica and Digitaria horizontalis accounted for about 99.7% of the entire infestation of the weed community. Cow bonechar decreases indaziflam pre-emergence herbicidal activity in tropical soil for weed control, most likely due to the high sorption and unavailability of the product in the soil solution.

摘要

向土壤中添加碳质材料（如牛骨炭）会影响施用的芽前除草剂（如茚虫草）的有效性。然而，牛骨炭如何影响茚满的生物利用度尚不清楚。本研究的目的是评估牛骨炭对茚虫草对热带土壤中杂草的除草活性的影响。除了用未经改良的土壤处理外，还将牛骨炭以 1、2、5、10 和 20 t ha ^-1均匀添加到表层土壤中。在施用茚虫草（75 g ha ^-1）后第 21 天，确定了损伤杂草水平、自发出现的杂草种类，并收集了每个采样单元中存在的杂草。仅 1.4 吨公顷^-1添加到土壤中的牛骨炭足以将杂草伤害水平降低 50%。从添加 2 t ha ^-1牛骨炭开始，茚虫草的施用对杂草控制无效，相当于不施用除草剂的处理。在所有处理中鉴定出八种杂草（3 个单子叶植物和 5 个双子叶植物）。Eleusine indica和Digitaria horizo​​ntalis约占杂草群落整个侵染的 99.7%。牛骨炭降低了热带土壤中用于控制杂草的茚虫草芽前除草活性，这很可能是由于该产品在土壤溶液中的高吸附性和不可用性。