The use-efficiency of phosphorus (P) in agriculture is high on the agenda because rock phosphate used for production of mineral fertiliser is a scarce and non-renewable resource. The strong retention of fertiliser P in soil reduces its availability and challenges the P use-efficiency in crop production. This study documents the long-term response in plant-available P to scenarios where soil P depletes because P fertilisation is omitted or where it builds up because of surplus P input.

Plant allocation of carbon (C) to rhizodeposition and mycorrhizae can improve their nutrient uptake. A pot experiment with four wheat genotypes showed that plant C allocation to rhizodeposition and mycorrhizae varied with soil nitrogen (N) and phosphorus (P) availability, affecting soil microbial biomass C and P, plant P uptake and grain yield.

Sowing maize in rotation with cotton is more frequent than in the past. We assessed its effects on soil properties, energy use and cotton yields in north-western New South Wales. Sowing maize into continuous cotton increased lint yields and lowered emissions but its impact in cotton–wheat was small. Maize is a suitable rotation crop for irrigated cotton in a two-crop sequence but is of little advantage in a three-crop sequence such as cotton–wheat–maize.

This paper is original and fits well within the research section with a scientific understanding of studies for forensic soils. This study analysed texture, elements and minerals of soils from the metropolitan region of Curitiba (Brazil) using dispersive energy X-ray fluorescence and Fourier transform infrared spectroscopy to potentially discriminate different soil sites and horizons. The soil sampling and analytical methods showed great potential for forensic studies, and might be employed in other states in Brazil and even in other countries.

Soil fungi participate in many ecological processes that affect plant growth and soil health. This study determined the effects of treatment with nitrogen–phosphorus fertiliser on the fungal composition and diversity under the ridge and furrow rainfall harvesting system in China. Fertiliser treatment changed the fungal composition and reduced diversity by affecting the soil nitrate-nitrogen and available phosphorus contents. These findings improve our understanding of soil biology processes under the ridge and furrow rainfall harvesting system.

Soil mineralogy and the effect of wet and dry cycles associated with rotation of flooded rice and sweet potato need to be evaluated to better understand soil nutrient reserves and development. Wet and dry cycles in this study showed leaching of Mn, Ca, Mg and Si elements from topsoil, while applications of phosphate and potassium fertilisers resulted in high residues in topsoils. Soil minerals contained high nutrient reserves, which could be considered to minimise fertiliser application.

These findings improve the understanding of the effects of different root morphological characteristics on soil shear strength and soil anti-scourability. Priority should be given to Pennisetum purpureum Schum. and Stylosanthes sp., which have higher root length densities, to increase the soil ecological effects. The results will provide a theoretical background for plant species selection in the dry-hot valley region.

Cattle excreta are the main source of nitrous oxide in world grasslands. Emissions were assessed in subtropical native grassland and we verified that the emission factor was almost 10 times higher for urine than for dung (0.74% vs 0.08%). Our findings highlight that both were much lower than the default 2% of IPCC’s Tier 1, which needs to be revised to avoid overestimation in national inventories of greenhouse gases.

An investigation was made of soil structure and porosity on generally poor-fertility sodic texture contrast soils under typical native and managed tropical grass pastures to determine effects of land use on soil physical properties. Deeper and greater root abundance, improved stable subsoil structure and increased macroporosity were observed under tropical pasture suggesting that tropical pasture roots may initiate favourable changes in these difficult soils, ultimately resulting in increased fodder production.