Balancing P and K inputs with crop needs is challenging in cropping systems applying poultry litter (PL) for N. We compared P and K balances of PL-amended organic and mineral-fertilized conventional systems over 13 yr. In organic systems, lower legume cover crop biomass (3,462 ± 421 vs. 4,691 ± 436 kg ha −1 ) and N contributions in a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation (Org2) led to 58% greater PL applications to corn than in a corn-soybean-wheat (Triticum aestivum L.) rotation (Org3); as did alfalfa (Medicago sativa L.) in a cornsoybean-wheat-alfalfa rotation (Org6). Greater Org2 and Org3 P inputs reduced harvest exports by 106 and 102 kg ha −1 , respectively, increased mean P balances by 209 kg ha −1 , and mean Mehlich 3 P concentrations by 9.6 mg kg −1 compared to Org6. Alfalfa exported 62% of P and 56% of K applied throughout the Org6 rotation. Due to alfalfa export, the annual P surplus was small (9 kg ha −1 ) and soil P was "optimum" in Org6. Soil test-based fertilizer application in tilled and no-till conventional systems with initially high soil P led to a -124 kg ha −1 P balance and optimum soil P. Fertilizer and PL K applications exceeding crop uptake led to positive K balances in all systems but greater retention of PL than fertilizer K. Legume cover crops or forages and increasing crop rotation length/complexity improved organic system P and K balances. Soil test-based fertilizer application in conventional systems reduced high soil test P while maintaining yields.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.