ABSTRACT

The transfer of Phosphorus (P) in water draining from agricultural lands to surface and ground waters is regarded as one of the serious agronomic problems in sandy Ultisol soils that occur in the southeastern agricultural plain of the USA. Therefore, enhancement of the P fertilizer use efficiency is considered through the amendment of such soils with organic and inorganic soil amendments. We studied the effect of biochar and coal fly ash amendment on the retention efficiency of soluble fertilizer P added to Ultisols. A sequential P fractionation with a series of acid and alkali extracts was carried out to soil samples added with coal fly ash, bio char and coal fly ash + biochar, applied with soluble P fertilizer, and incubated for 30 days. As per our results, soil amendments reduced the readily leachable fractions of P in soil through a variety of retention and fixation pathways. Coal fly ash converted 41% of P into moderately labile Calcium (Ca) bound P. Biochar could retain 31% of P as less labile organic P and 26% as Ca bound P. The coal fly ash + biochar application significantly reduced the leachable P fraction by converting 93% of the P into labile, moderately labile and residual P pools. Coal fly ash and biochar soil amendments were recommended to reduce the leaching loss of P from acidic sandy Ultisol.

摘要

从农田排水到地表水和地下水中的磷 (P) 转移被认为是美国东南部农业平原沙质 Ultisol 土壤中严重的农艺问题之一。因此，考虑通过有机和无机土壤改良剂对此类土壤进行改良来提高磷肥的利用效率。我们研究了生物炭和粉煤灰改良剂对添加到 Ultisol 中的可溶性肥料 P 的保留效率的影响。对添加粉煤灰、生物炭和粉煤灰+生物炭的土壤样品进行一系列酸和碱提取物的连续磷分馏，施用可溶性磷肥，培养30天。根据我们的结果，土壤改良剂通过各种保留和固定途径减少了土壤中易浸出的 P 部分。粉煤灰将 41% 的 P 转化为中度不稳定的钙 (Ca) 结合磷。生物炭可以保留 31% 的磷作为不太不稳定的有机磷和 26% 的钙结合磷。粉煤灰 + 生物炭的应用显着降低了可浸出的 P通过将 93% 的 P 转化为不稳定、中度不稳定和残留的 P 池来获得分数。推荐粉煤灰和生物炭土壤改良剂以减少酸性沙质 Ultisol 中 P 的淋失损失。粉煤灰 + 生物炭应用通过将 93% 的 P 转化为不稳定、中等不稳定和残留的 P 池，显着降低了可浸出的 P 分数。推荐粉煤灰和生物炭土壤改良剂以减少酸性沙质 Ultisol 中 P 的淋失损失。粉煤灰 + 生物炭应用通过将 93% 的 P 转化为不稳定、中等不稳定和残留的 P 池，显着降低了可浸出的 P 分数。推荐粉煤灰和生物炭土壤改良剂以减少酸性沙质 Ultisol 中 P 的淋失损失。