Nitrogen and phosphorus uptake from solid and liquid pig manure in perennial and annual cropping systems

Abstract

Applying pig manure in excess of crop demand can result in nutrient loss to water bodies. We studied the effect of liquid and solid pig manures and their N- and P-based application rates on yield and nutrient uptake in annual and perennial cropping systems for 3 yr. The experiment had a split-plot design with five nutrient management treatments including liquid-N (annual N-based liquid pig manure), liquid-P (P-based liquid pig manure once every 5 yr), solid-N (annual N-based solid pig manure), solid-P (P-based solid pig manure once every 5 yr), and control (no manure). The liquid-P treatment showed high apparent nitrogen and phosphorus recovery (ANR and APR, respectively) in each cropping system and yields similar to that of the liquid-N treatment. The solid-N treatment had the smallest ANR in the perennial cropping system (9%–27%) and also the smallest APR in both cropping systems (typically <4%) possibly due to N deficiency and high P application rate. The current formula for estimating organic N mineralization overestimated the available N, particularly for solid pig manure, reducing crop yield. Based on the ANR obtained in this study, a more appropriate coefficient is 10%–15% of the organic N from solid pig manure for no-till perennial cropping systems.