Publication Date
1993
Description
Renovation of old· grass pastures by light cultivation to improve the availability of soil N has given unpredictable results. A better understanding of N movement in the soil-plant system is needed to develop management for long-term productivity. Our work traced the movement of a pulse input of labelled N through the soil-grass system with and without annual light cultivation. Labelled N from the mineral N pool peaked first in the microbial biomass, then in roots, tops, litter, and soil organic matter. Annual light cultivation reduced the uptake of labelled N by grass. It initially increased immobilisation of 15N into fine litter and later into soil organic matter. Effects on the soil microbial biomass N were not detectable. The effect of soil moisture on renovation warrants investigation. Light cultivation cannot be recommended yet as a reliable way to renovate grass pastures.
Citation
Vallis, I; Catchpoole, V R.; and McGill, W B., "Redistribution of a Pulse Input of 15N in a Sown Perennial Subtropical Grass Pasture With and Without Light Cultivation" (2024). IGC Proceedings (1993-2023). 16.
https://uknowledge.uky.edu/igc/1993/session42/16
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Redistribution of a Pulse Input of 15N in a Sown Perennial Subtropical Grass Pasture With and Without Light Cultivation
Renovation of old· grass pastures by light cultivation to improve the availability of soil N has given unpredictable results. A better understanding of N movement in the soil-plant system is needed to develop management for long-term productivity. Our work traced the movement of a pulse input of labelled N through the soil-grass system with and without annual light cultivation. Labelled N from the mineral N pool peaked first in the microbial biomass, then in roots, tops, litter, and soil organic matter. Annual light cultivation reduced the uptake of labelled N by grass. It initially increased immobilisation of 15N into fine litter and later into soil organic matter. Effects on the soil microbial biomass N were not detectable. The effect of soil moisture on renovation warrants investigation. Light cultivation cannot be recommended yet as a reliable way to renovate grass pastures.
