Nutrient Release Dynamics in Argentinean Pampean Soils Amended with Composts under Laboratory Conditions

Abstract

Composted manure is the greatest nitrogen (N) source in organic agriculture, where the use of chemical fertilizers, except the use of rock phosphate as P source, is not allowed. The aim of this study was to evaluate the effect of the soil type and compost characteristics on the potential rates of mineralization and on the kinetics of the nitrogen (N), phosphorus (P), and carbon (C) release patterns. For this, an aerobic incubation study was conducted over the course of 119 days at 25 °C using two different composts as amendments: a compost from biosolids and wood shavings (CRUB), and a compost from poultry manure with wheat straw (CSP). The composts were incorporated into two different soils of contrasting texture, sandy loam (S1) and silty clay loam (S2), at the dose of 160 kg N ha−1. Samples were collected eight times during the incubation period. The N and C dynamics were studied separately according to the different soil type. In both soils, a predominance of the nitrification process immediately after compost application was observed, showing a higher mineralization in the sandy loam soil, this trend being followed by a decrease and even an immobilization process, associated with stable organic materials such as compost. Moreover, both composts presented high contents of available P, but without exceeding 50 mg P kg−1, due to the slow release from the stable organic P fractions present in compost. The results obtained showed that despite the initial mineralization, both composts showed a significant period of N immobilization after their application into the pampean soils, which makes it necessary to anticipate their incorporation to avoid this lack period for crops. Furthermore, the application of these composts to the pampean soils implied an incorporation of available P, but with a slow release that avoided overfertilization, but also reducing N:P ratio and producing a relative deficit of N. Therefore, the results obtained suggested that it is necessary to study nutrient mineralization processes of the amendments prior to their use, according to the edaphoclimatic condition of each crop, in order to predict the release dynamics on soils and the fertilization potential to minimize potential environmental impacts.

Zonificación por aptitud de suelo y diagnóstico de la fertilidad actual de la sabana de Bogotá para el cultivo de lechuga

“…El análisis de fertilidad química del suelo refleja el efecto aparente del exceso de fertilización, práctica con la cual se supera ampliamente los requerimientos de los cultivos, y en particular, de la lechuga, lo cual confirma lo reportado por Forero y Escobar (2010), quienes además argumentan que tales excesos pueden ser de las principales causas de deterioro del suelo y del medio ambiente. Ello se explica en parte porque los agricultores aplican el fertilizante para una cosecha, pero la mineralización y la disponibilidad final de los nutrientes pueden tardar mucho tiempo, más allá del ciclo de cultivo (Orden et al, 2022). Una práctica recomendable para el cultivo de lechuga es la aplicación en enmiendas para corregir el pH, especialmente por problemas de acidez.…”

“…Si la CE llegase a niveles por encima de 2 dS/m y la concentración de sodio aumentara, el efecto sería perjudicial para la nutrición de las plantas, aunque un bajo nivel de estrés (euestrés) podría estimular una mejor calidad del producto a cosechar (Carillo et al, 2021) que los suelos de la unidad RMO, por su mayor salinidad y su condición superficial, requieren un manejo conservacionista. Los suelos RLQ y RMO presentan mayores contenidos de MOS y bajos niveles de pH, condiciones que están relacionados con prácticas de fertilización y abonado que, de no manejarse técnicamente, pueden acarrear problemas de acumulación de sales y desbalances nutricionales (Orden et al, 2022). En contraste, los suelos RMR presentan menores contenidos de MOS, pero debido a que está asociado a un pH más alto, se puede manejar agronómicamente con un abonado adecuado.…”

Effects of microbial inoculant and additives on pile composting of cow manure

“…Composting is an effective way to recycle organic solid waste, bringing together crop planting and recycling ( Briški et al, 2003 ; Liao et al, 2019 ; Hu et al, 2022 ). To improve soil fertility in saline-alkali land, the application of organic fertilizer is particularly effective ( Orden et al, 2022 ; Zou et al, 2022 ). Aerobic composting is an effective way to realize the reduction, reuse, and harmless treatment of organic waste.…”