Residual effect of pig slurry on common carpet grass pasture

Daiane C K Albuquerque,Mario Miranda,Simone M Scheffer-Basso,Valdirene Zabot,Pedro A V Escosteguy,Karen D Brustolin-Golin

doi:10.1590/1807-1929/agriambi.v21n6p374-378

Abstract

ABSTRACT This study investigated the residual effects of pig slurry (PS) applied to common carpet grass pasture (Axonopus affinis) for two years (September 2008-March 2010) on dry matter yield and forage-nitrogen uptake from October 2010-May 2011. A field experiment was conducted in a randomized complete block design with four replications. The treatments were 102, 204, 306, 408, and 510 m3 ha-1 pig slurry applied for two years; one mineral nitrogen rate (1,250 kg ha-1 ammonium nitrate) for two years; and no nitrogen fertilization (control). The pasture was cut at intervals of 48, 34, 43 and 69 days, which corresponded to 266, 300, 343, and 412 days after the last fertilizer application, respectively. Dry matter yield increased by 398 kg ha-1 for each 100 m3 of PS applied, the equivalent of 317 and 564 kg ha-1 for each 100 kg ha-1 of inorganic and organic N applied, respectively. The residual effect of PS on dry matter yield and forage-nitrogen uptake ranged from 11-45% and 8-40%, respectively, indicating a gradual release and availability of N in PS, which can help reduce the amounts of nitrogen applied to pasture.

Highlights

Pig slurry (PS) is an organic alternative to chemical nitrogen (N) fertilizers that can increase production of winter and summer crops (Seidel et al, 2010; Moraes et al, 2014; Basso et al, 2016) and of cover crops (Aita et al, 2006)
A significant part of the organic N retained in the soil after PS application is derived from immobilized ammonium-N, which is slowly released over many years (Sorensen & Amato, 2002)
Some of the PS ammonium-N may have been lost or fixed on clays shortly after its application and some of the organic-N may have been allocated in stems, leaves, and roots, which is made available over time through senescence

Summary

Introduction

Pig slurry (PS) is an organic alternative to chemical nitrogen (N) fertilizers that can increase production of winter and summer crops (Seidel et al, 2010; Moraes et al, 2014; Basso et al, 2016) and of cover crops (Aita et al, 2006). A significant part of the organic N retained in the soil after PS application is derived from immobilized ammonium-N, which is slowly released over many years (Sorensen & Amato, 2002). These N forms may remain in the soil at the end of the growing season, benefitting subsequent crops, which is known as the residual effect. It has been suggested that manures may only have a benefit on soil productivity, over and above their nutrient content, when large inputs are applied over many years (Edmeades, 2003). Pastures only increased nutrient levels in the leaves and soil starting a year after application (Teixeira et al, 2012) Rich) Stapf. pastures only increased nutrient levels in the leaves and soil starting a year after application (Teixeira et al, 2012)

Methods

Results

Conclusion