Agroscope, Field-Crop Systems and Plant Nutrition, Research Division Plant Production Systems, Route de Duillier 50, P.O. Box 1012, CH-1260, Nyon, Switzerland.
Aix Marseille Univ, Avignon Université, CNRS, IRD, IMBE, Marseille, France.
J Environ Manage. 2021 Oct 1;295:113092. doi: 10.1016/j.jenvman.2021.113092. Epub 2021 Jun 26.
Recycling phosphorus (P) is crucial to meet future P demand for crop production. We investigated the possibility to use calcium phosphite (Ca-Phi) waste, an industrial by-product, as P fertilizer following the oxidation of phosphite (Phi) to phosphate (Pi) during green manure (GM) cropping in order to target P nutrition of subsequent maize crop. In a greenhouse experiment, four GM crops were fertilized (38 kg P ha) with Ca-Phi, triple super phosphate (TSP) or without P (Control) in sandy and clay soils. The harvested GM biomass (containing Phi after Ca-Phi fertilization) was incorporated into the soil before maize sowing. Incorporation of GM residues containing Phi slowed down organic carbon mineralization in clay soil and mass loss of GM residues in sandy soil. Microbial enzymatic activities were affected by Ca-Phi and TSP fertilization at the end of maize crop whereas microbial biomass was similarly influenced by TSP and Ca-Phi in both soils. Compared to Control, Ca-Phi and TSP increased similarly the available P (up to 5 mg P kg) in sandy soil, whereas in clay soil available P increased only with Ca-Phi (up to 6 mg P kg), indicating that Phi oxidation occurred during GM crops. Accordingly, no Phi was found in maize biomass. However, P fertilization did not enhance aboveground maize productivity and P export, likely because soil available P was not limiting. Overall, our results indicate that Ca-Phi might be used as P source for a subsequent crop since Phi undergoes oxidation during the preliminary GM growth.
回收磷 (P) 对于满足未来作物生产对 P 的需求至关重要。我们研究了在绿肥 (GM) 种植期间将亚磷酸 (Phi) 氧化为磷酸盐 (Pi) 后，利用工业副产物亚磷酸钙 (Ca-Phi) 废物作为 P 肥料的可能性，以满足后续玉米作物的 P 营养需求。在温室实验中，四种 GM 作物在沙质和粘土地中分别用 Ca-Phi、过磷酸钙 (TSP) 或不施 P（对照）（38kgP ha）施肥。收获的 GM 生物量（Ca-Phi 施肥后含有 Phi）在玉米播种前被掺入土壤中。含有 Phi 的 GM 残渣的掺入减缓了粘土地中有机碳的矿化和沙土地中 GM 残渣的大量损失。在玉米作物结束时，Ca-Phi 和 TSP 的施肥影响了微生物酶活性，而 TSP 和 Ca-Phi 在两种土壤中同样影响了微生物生物量。与对照相比，Ca-Phi 和 TSP 相似地增加了沙质土壤中有效 P（高达 5mgP kg），而在粘土地中仅 Ca-Phi 增加了有效 P（高达 6mgP kg），表明 GM 作物期间发生了 Phi 氧化。因此，在玉米生物量中未发现 Phi。然而，P 施肥并没有提高地上玉米生产力和 P 输出，可能是因为土壤有效 P 没有限制。总体而言，我们的结果表明，由于在初步 GM 生长期间 Phi 会发生氧化，因此 Ca-Phi 可用作后续作物的 P 源。
