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Full-Text Articles in Physical Sciences and Mathematics

Toward Better Minimum Tillage For South-Coastal Sandplain Soils, W L. Crabtree Aug 1990

Toward Better Minimum Tillage For South-Coastal Sandplain Soils, W L. Crabtree

Resource management technical reports

Seventeen farmers compared their conventional cropping practices with some form of minimum tillage cropping. The minimum tilled crops yielded 21 percent less grain than the conventionally sown crops. The reasons for these decreased yields were in most cases related to inexperienced management. The minimum tilled treatments usually had very poor weed kill strategies which often resulted in large weeds at sowing, very cloddy seed-beds, and numerous insects in the young crops.


Phosphorus Retention Of Sandy Horticultural Soils On The Swan Coastal Plain, Ian Mcpharlin, Neil Delroy, Bob Jeffery, Greg Dellar, Maurice Eales Jan 1990

Phosphorus Retention Of Sandy Horticultural Soils On The Swan Coastal Plain, Ian Mcpharlin, Neil Delroy, Bob Jeffery, Greg Dellar, Maurice Eales

Journal of the Department of Agriculture, Western Australia, Series 4

Soils can be ranked according to their phosphorus retention capacity by the phosphorus retention index (PRI). This is the ratio of phosphorus adsorbed by soil to that remaining in solution under a set of standard conditions. Although it is a laboratory measurement, the PRI seems to be a good indication of what happens in practice.


An Economic Model For Evaluating Strategies On The South Coast Of W.A. Which Reduce Wind Erosion : Documentation, A D. Bathgate Jan 1990

An Economic Model For Evaluating Strategies On The South Coast Of W.A. Which Reduce Wind Erosion : Documentation, A D. Bathgate

Resource management technical reports

The sandplain region on the south coast has predominately sandy soils which are subject to erosive winds when ground cover is likely to be scarce. This can often result in production losses of crop and pasture. There is concern that wind erosion will lead to the depletion of the soil resource in the long term. The model is multi-period linear programming with a planning horizon of 10 years. Effects of wind erosion on production can be imposed on the model for the first five years after the erosion event.