دانلود رایگان مقاله انگلیسی تاثیر خاک ورزی بر تولید محصولات کشاورزی در مناطق گرمسیر به سمت آب هوای خشک - اشپرینگر 2018

Abstract

Strategic tillage (ST), an occasional tillage in a continuous no-till (NT) farming system, is already being utilized by many landholders in the Northern Grains Region (NGR) of Australia to control weeds. But the impact on productivity (yield), both short- and long-term, has been largely under investigated. This study focused on yield data from 14 on-farm ST in NT experiments from 2012 to 2014 (3 years/4 seasons) and the comparison of the re-interpreted results of a long-term (27 years) tillage experiment. This study explored production impacts of tillage on long-term NT systems over the short and longer term. Results from tillage-frequency studies across the NGR demonstrated that overall grain yield was not significantly impacted. A long-term tillage trial at Biloela showed wheat (Triticum aestivum) and sorghum (Sorghum bicolor) grain yields were similar across no till, stubble mulch and reduced tillage treatments, these in turn were all significantly higher than aggressive tillage without stubble retention treatments. Dealing with increased herbicide resistance often associated with reduced tillage and no-till systems poses a real time issue with landholders in the NGR. This analysis of historical yield data together with the more recent strategic tillage data can aid in selecting the appropriate soil management option by providing tillage impacts on yield.

Conclusion

The analysis of two sets of field experiments demonstrated that an occasional or strategic tillage within a no-till farming system may have an insignificant impact on grain yield in the northern grain growing region of eastern Australia. The results bring some scientific rigour to management changes already being implemented in these farming systems. This study is however, limited to the eastern part of Australia with CA tillage practices on predominantly well-structured clay soils. It only included two other soil types, which limits the robustness of the above conclusion. Future research on a wider variety of soil types in the region is recommended.

By design this manuscript focussed only on the yield mpacts of tillage practices in NT systems. Soil health impacts must always be factored in when considering tillage application in NT systems. The economic decision to implement an occasional strategic tillage is also a subjective farm management decision. They can be based on a number of factors such as: herbicide resistance; chemical cost vs tillage cost, and weather patterns. Hence, it is prudent to continue the assessment of CA practices within Queensland and wider Australia to build a quantifiable database for future decision making.