ABSTRACT

Previous studies have reported two major methods of increasing PR solubility; calcination and partial acidulation. In addition, soil water condition would influence the solubility of P fertilizers. However, the effects of local P fertilizers, namely calcined PR (CPR) and partially acidulated PR (PAPR) on rice yield under different soil water conditions have not been explored comprehensively. The aims of the present study were to evaluate the effects of local P fertilizers produced from PR in Burkina Faso under different soil water conditions and to propose local fertilizers with optimal application rates for different soil water conditions. The field experiments were conducted at four farmers’ fields with different ground-water levels (GWL). CPR, PAPR, and superphosphate were applied at rates of 0, 7.6, 15.3, and 30.5 kg P ha⁻¹, respectively. Superphosphate mostly consists of water-soluble P fraction (WP), PAPR of WP and alkaline ammonium citrate-soluble P fraction (SP), and CPR of SP and 2% citric acid-soluble P fraction (CP). The solubility is in the order of WP > SP > CP. The GWL was monitored during the growing season, and yield components were observed. Results of multiple regression analysis showed that WP influenced grain yield under all soil water conditions, whereas SP only influenced grain yied at mean GWL > −24.7 cm. Therefore, PAPR with high WP has an advantage over CPR in the field with GWL > −18.7 cm, and both CPR and PAPR are effective in fields with GWL > −6.5 cm. The optimal application rate was 14.4 kg P ha⁻¹ as WP in the field with low GWL (mean −29.2 cm), 15.2–15.9 kg P ha⁻¹ as WP + SP in the field with middle GWL (mean −24.7 to −18.7 cm), and 11.1 kg P ha⁻¹ as WP + SP in the field with high GWL (mean −6.5 cm). According to the results, the optimal fertilizer types and application rates differ according to the soil water conditions.

摘要

先前的研究报告了两种增加 PR 溶解度的主要方法；煅烧和部分酸化。此外，土壤水分状况也会影响磷肥的溶解度。然而，当地磷肥，即煅烧磷肥（CPR）和部分酸化磷肥（PAPR）在不同土壤水分条件下对水稻产量的影响尚未得到全面探讨。本研究的目的是评估布基纳法索 PR 生产的当地磷肥在不同土壤水分条件下的效果，并针对不同土壤水分条件提出具有最佳施用量的当地肥料。田间试验在四个不同地下水位 (GWL) 的农田中进行。CPR、PAPR 和过磷酸钙的施用率为 0、7.6、15.3 和 30.5 kg P ha^-1，分别。过磷酸钙主要由水溶性P部分（WP）、WP的PAPR和碱性柠檬酸铵可溶P部分（SP）、SP的CPR和2%柠檬酸可溶P部分（CP）组成。溶解度的顺序为 WP > SP > CP。在生长季节监测 GWL，并观察产量构成。多元回归分析结果表明，在所有土壤水分条件下，WP 影响粮食产量，而 SP 仅影响平均 GWL > -24.7 cm 的粮食产量。因此，高WP的PAPR在GWL>-18.7cm的领域比CPR有优势，在GWL>-6.5cm的领域CPR和PAPR都有效。最佳施用量为 14.4 kg P ha ^-1作为 WP 在低 GWL（平均 -29.2 cm）、15.2-15.9 kg P ha ^{-1 的}田间作为具有中等 GWL 的田地中的 WP + SP（平均 -24.7 至 -18.7 cm），以及 11.1 kg P ha ^-1作为具有高 GWL 的田地中的 WP + SP（平均 -6.5 cm）。结果表明，最佳肥料种类和施用量因土壤水分条件而异。