The effects of three different land uses (dairy grazing, winter potatoes, and winter greens [spinach, cauliflower or cabbage] production) on soil mineral N contents and nitrate leaching losses from late June to early October 2000 were investigated on 18 commercial paddocks. All paddocks were in the Pukekohe area (approximately 50 km south of Auckland) on Patumahoe clay loam soils and received typical management practices for the district. On average, dairy paddocks received the least amount of N fertiliser during the study period (84 kg N ha -1 ), had the lowest soil mineral N content in June (32 kg N ha -1 ) and had the lowest leaching loss (15 kg N ha -1 ). On average, potato paddocks received the greatest amount of N fertiliser (481 kg N ha -1 ), had the greatest soil mineral N content in June (184 kg N ha -1 ) and had the greatest leaching loss (114 kg N ha -1 ). The winter greens paddocks were intermediate between the other land uses. Leaching losses from the potato and greens paddocks were the result of large applications of fertiliser N before winter and the rapid mineralisation of residues from the previous greens crops.
Grazing of winter forage crops can cause extensive compaction of soils that may reduce re-growth of crops and lead to large emissions of nitrous oxide (N2O). A field trial was undertaken to investigate the effects of cattle grazing at three soil moisture contents on N2O emissions and dry matter (DM) production of a winter forage crop established by intensive (IT), minimum (MT), or no tillage (NT) practices. A multi-grazing triticale (cv. Doubletake) was sown in the main tillage plots in March 2003. In June, the tillage plots (three replicates) were each divided into six split plots and additional treatments were imposed: simulated treading (+/-); soil moisture at treading (< field capacity (FC); FC; and >FC); and urine (+/-). Tillage practice and soil moisture content at treading affected soil compaction. The greatest increase in surface soil (0-7.5 cm) bulk density occurred in IT plots treaded at >FC. Treading wet soil greatly increased (up to 8 times) the amount of N2O emitted. The highest cumulative N2O emissions were from IT (14.9 kg N/ha) and MT (12.7 kg N/ha) urine-applied plots treaded at >FC. There was no difference in N2O emitted from treaded FC. Treading at FC also caused a significant loss of DM production in the IT plots but not in the MT plots. DM production in the NT plots was unaffected by treading. Establishing winter forage crops by direct drilling may be an important management option to mitigate N2O emissions and maintain high DM production of grazed forages, as will avoiding grazing when soils are wet. Keywords: forage crops, grazing, nitrous oxide, soil compaction, tillage, urine
The effects of soil and residue management factors (tillage postharvest crop residue management and winter cover crops) and crop rotation (wheat following two barley crops wheat following ryegrass) on take all were compared in a 3year field trial in Canterbury Incidence of takeall was very high in plots that had previously grown barley and very low in plots that followed ryegrass Takeall incidence was also much greater in plots that were disced than in plots that were directdrilled Differences in soil pH and in plant emergence were also recorded between disced and directdrilled plots but there was no evidence that they caused the increased levels of takeall There was a tendency towards reduced yields in the disced plots that had severe levels of takeall
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.