The Hydrogeological Landscape (HGL) framework provides a structure for understanding how salinity manifests in the landscape, how differences in salinity are expressed across the landscape and how salinity may best be managed. This is the first approach to specifically address all three manifestations of salinity: land salinity, in-stream salt load and in-stream salt concentration. The HGL framework is an expert system that integrates the spatial variability of landscape characteristics and salinity processes to produce a salinity hazard assessment for any given area.

Accurate crop management at a field level requires understanding and quantification of the relationships between soil properties and crop yield. The present paper discusses the successful implementation of an innovative non-linear parametric modelling approach for quantification of the agronomic influences of individual and interaction between pairs of soil properties on wheat yield. The quantification of the soil-related yield-limiting factors is an important step towards successful precision application for farm inputs.

Natural organic matter could be a vector by which pollutants enter aquatic systems. The present study characterised the dissolved organic matter (DOM) released during soil waterlogging and under progressive reducing conditions. The results indicate high DOM release after oxygen depletion induced by soil waterlogging and show DOM enrichment with polar functional groups under iron-reducing conditions. These changes in DOM composition could have important consequences on the solubility and mobility of metals in soil.

Laboratory incubations and field measurements have provided valuable information on the production of green-house gases. However, information about the effects of pre-incubation and closure time on soil-induced gas emissions is currently limited. Our findings showed that different closure times and pre-incubation times altered gas emissions from incubated soils. A standardised procedure to investigate gas fluxes is needed for application to other studied soils.

In this study, responses of rice yield and soil physicochemical and biological health were investigated after application of biofertiliser and enriched biocompost, where significant increases in rice yield and improved soil organic carbon, soil nutrients and biological health were observed. Incorporation of biofertiliser and biocompost can substitute for 75% of inorganic N and P fertilisers. Fraction 2 (labile carbon) of total organic carbon, total P, available K, microbial biomass carbon and phosphate-solubilising bacteria were identified as indicators of soil quality to assess the efficacy of biofertiliser and biocompost incorporation in Inceptisols under rice cultivation.

This study investigated responses of soil enzyme activity, soil micro-organisms, muskmelon root growth and muskmelon fruit yield and quality to different levels of film covering, drip pipe density and different lower limits of irrigation in a greenhouse experiment. The results showed that, half film covering, irrigation at 80% field capacity and one pipe for two rows improved the root-zone soil environment, muskmelons yield and fruit quality in the greenhouse.

Land use pattern regulates the relative contribution of ammonia-oxidising archaea (AOA) and ammonia-oxidising bacteria (AOB) to ammonia oxidation in acidic soils. We found that AOA played the predominant role in ammonia oxidation in acidic forest and paddy soils, whereas AOB mainly regulated the ammonia oxidation in acidic upland agricultural soils. Thus, the contributor of ammonia oxidation in acidic soils can be manipulated via regulation of the soil moisture content.

Soil organic matter (SOM) plays a key role in maintaining soil productivity but directly altered by climate. The combinations of two SOM quality techniques (DSC-TG analysis and density fractionation) showed that the SOM content was mainly limited by annual precipitation and low clay content especially in the dry forest soils. These techniques provided better characterisation of SOM quality which determines C-sequestration capacity of the Mudumalai tropical forest soils.

A 5-year field study was conducted to evaluate the effect of tillage, crop establishment and residue management on soil biochemical changes, soil fertility and wheat yield in rice-wheat cropping systems. Zero tillage with residues retention produced was 6–10% higher yield than in conventional tillage and Zero tillage without residues retention. Substituting intensive tillage with ZT and residue retention improved soil enzymatic activity. Conservation agriculture practices have potential to improve soil health in rice-wheat system.

Soil quality and emissions of carbon dioxide from soil are determined largely by the decomposition of soil organic matter. In this 812-day incubation study of volcanic ash topsoils from oil palm plantations, we found that decomposition was influenced to similar extents by biochemical recalcitrance and physical protection. The results could help improve models used to predict how soil organic carbon content changes under changed management or climate.