Knowledge of optimal values of soil physical quality (SPQ) indicators is essential for enhancing crop productivity and environmental health. In this study, the impact of long-term perennial pasture grasses, continuous field crop cultivation and fallow land uses on selected SPQ indicators was investigated. The land use under perennial pasture grasses better improved the SPQ than the other land uses implying that better crop productivity and environmental health would be achieved under the land use.

Soil compaction is reluctantly dealt with by farmers because of the high cost involved in ripping the soil that requires high fuel consumption. This paper discusses the best configuration for tines in a shallow leading tine ripper and compares it with the conventional ripper. Different tine arrangements including offset with different tine depths were studied. The soil tilth and clod size produced by SLT and conventional rippers were also measured and compared. The SLT ripper significantly uses less fuel and produce better tilth resulting in improved plant establishment and water distribution.

Incorporation of crop residue in soil can increase phosphorus availability but it is necessary to evaluate how it is modulated by soil properties. We added residues of faba bean, chickpea and white lupin differing in P concentration to three soils with different texture, organic matter content and pH. Our study indicated that most effects of legume residue addition on microbial activity and growth and soil P dynamics can be generalised across the soils, although they differ in physical and chemical properties.

The buffering capacity of a soil must be known in order to predict changes in its pH due to acidic or alkaline inputs, and to model the many pH-dependent processes in soils. From a study which included soils differing in organic matter, texture, and mineralogy, we conclude that organic matter has a dominant influence on pH buffering. As a result, management practices that deplete organic matter can make soil more vulnerable to acidification.

Field-scale variation of soil nutrients in grassland is becoming important because of the use of soil-nutrient information as a basis for policies such as the recently introduced EU Nitrates Directive. The average soil test phosphorus (STP) values in both fields are much greater than the recommended agronomic optimum STP status in Ireland of 8 mg L^–1. Meanwhile, grazing animals cause a weak spatial autocorrelation of soil properties. Attention should be paid to long-term poultry application, which can caused potential environmental risk in grassland management.

Maintaining soil carbon contents is important for agricultural sustainability, and recent research has measured losses of soil carbon in intensively grazed soils in New Zealand. We measured the effect of cow urine application to pasture soil on carbon dioxide fluxes and found that treatment with cow urine lead to losses of soil carbon by increasing soil carbon decomposition. Therefore, urine deposition may be one of the factors decreasing soil carbon in intensively grazed pastures.

Biochar application in poor or acidic soils has often shown amazing effects on crop yield, which seemed a win-win strategy for ensuring food security and mitigating global climate warming. We studied the effects of biochar on alkaline soils in high-yielding agricultural fields which was poorly understood. However, the limited effects of biochar on soil nutrient, water and crop yield suggest that the positive effects of biochar application may only occur in some special conditions.

Biosolids (treated sewage sludge) are a rich source of plant nutrients which are regulated in their application to land according to EPA estimates of their plant available nitrogen (PAN). Direct determination of PAN is usually achieved through tedious measurement of nitrogen pathways, requiring many types of analyses. We have demonstrated the power of an alternative simple field calibration method with considerable potential for regulators, and in the process have provided much needed data on two biosolids from Victoria, Australia.

A new mathematical solution for soil oxygen concentration profiles with microbial and root sinks was used to calculate the finite depth of extinction at which the concentration becomes zero. A critical air-filled porosity at which the oxygen penetrates to infinite depth was found, and used to develop a unifying relationship for air-filled porosity and extinction depth. The new solution was used to consider the effects of air-filled porosity on soil biochemical processes.

Degradation rate of lake wetlands of the Huitengxile grassland (Inner Mongolia Plateau, China) has increased over the past years. We reported the distribution and abundance of ammonia-oxidizing microorganisms in surface soils of Huitengxile grassland and found that ammonia-oxidizing archaea community in wetland systems are more sensitive to drying up process of wetland ecosystem. Our results filled a blank in microbial study of degraded wetlands of north China, and are instructive for understanding of the mechanism of ammonia oxidation process and expanding ammonia-oxidizing microbial genetic resources.