Publication Date
1997
Description
In southern Australia pastures precede wheat in many rotations. In recent years the quality (legume content) of many pastures has declined and the value of pastures in rotation with cereals has been questioned. This research aims to develop a more complete understanding of the impact of pastures on crop production through greater knowledge of the below ground processes of soil water and soil inorganic nitrogen. In this study, the impacts of annual barley grass (Hordium leporinum) and barrel medic (Medicago truncatula) pastures on soil water and inorganic nitrogen status at the start of a subsequent wheat growing season were investigated in an existing field study located at Roseworthy, South Australia. Gravimetric contents of water, nitrate-N and ammonium-N were measured for eight depth layers within the 0-180 cm soil profile and converted to a volumetric basis. The amounts of water and nitrate-N in the soil at the start of the next growing season were significantly higher after medic pasture than grass pasture. Soil nitrate-N following a legume dominant pasture (87 kg nitrate-N ha-1) was more than double the amount following a grassy pasture (42 kg nitrate-N ha-1) in the top 60 cm of soil. Soil water was greater following legume pasture, particularly at depths greater than 60 cm. No significant effect of pasture type was noted on ammonium-N or the total inorganic-N fraction (nitrate-N + ammonium- N).
Citation
Baldlock, J A.; Bellotti, W D.; Moore, A D.; and Yunusa, I, "Impacts of Grazed Pastures on Soil Water and Nitrogen Status in Cropping Systems" (2024). IGC Proceedings (1993-2023). 21.
https://uknowledge.uky.edu/igc/1997/session19/21
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Impacts of Grazed Pastures on Soil Water and Nitrogen Status in Cropping Systems
In southern Australia pastures precede wheat in many rotations. In recent years the quality (legume content) of many pastures has declined and the value of pastures in rotation with cereals has been questioned. This research aims to develop a more complete understanding of the impact of pastures on crop production through greater knowledge of the below ground processes of soil water and soil inorganic nitrogen. In this study, the impacts of annual barley grass (Hordium leporinum) and barrel medic (Medicago truncatula) pastures on soil water and inorganic nitrogen status at the start of a subsequent wheat growing season were investigated in an existing field study located at Roseworthy, South Australia. Gravimetric contents of water, nitrate-N and ammonium-N were measured for eight depth layers within the 0-180 cm soil profile and converted to a volumetric basis. The amounts of water and nitrate-N in the soil at the start of the next growing season were significantly higher after medic pasture than grass pasture. Soil nitrate-N following a legume dominant pasture (87 kg nitrate-N ha-1) was more than double the amount following a grassy pasture (42 kg nitrate-N ha-1) in the top 60 cm of soil. Soil water was greater following legume pasture, particularly at depths greater than 60 cm. No significant effect of pasture type was noted on ammonium-N or the total inorganic-N fraction (nitrate-N + ammonium- N).
