Soil Properties under Nitrogen‐ vs. Phosphorus‐Based Manure and Compost Management of Corn

Abstract

© Soil Science Society of America. Concerns about P enrichment of soil, streams, and lakes, NH 3 emissions from surface-applied manure, and increasing N fertilizer costs have resulted in greater adoption of manure incorporation at rates that approximate P removal. A 5-yr field study was conducted comparing the influence of annual spring applications of N- vs. P-removal-based compost (74 and 46 Mg ha -1 wet basis, respectively), liquid dairy manure (196 and 68 kL ha -1 , respectively), and sidedress N fertilizer (0 and 112 kg ha -1 ) on soil pH, soil organic matter (SOM), respiration, NO3-N, and soil test P (STP) and K (STK) in a corn (Zea mays L.) silage cropping system on a calcareous central New York soil. Manure was incorporated with tillage in the P-removal-based system. After 5 yr, soil pH (0-20 cm) remained unchanged compared with its initial level in 2001 regardless of the application rate or source. In P-based manure and inorganic N plots, SOM declined with time but increased by 4 g kg -1 with N-based compost. Solvita CO2 respiration increased only for N-based compost (41 g mg -1 ), which was greater than for P-based manure (32 g mg -1 ) in April 2005. After 5 yr, topsoil (0-20 cm) STP and STK were greatest with N-based compost and manure. These results show the benefits of compost application for SOM accumulation and respiration, the benefits of P-based applications for management of STP and STK, and the negative impact on SOM because of tillage incorporation of manure at P-based rates. Manure injection rather than tillage-based incorporation might counteract this negative impact.