Alkaline stress imposes significant constraints on agriculture by reducing nutrient availability and inhibiting plant growth. This study examines the physiological and biochemical responses of chickpea (Cicer arietinum L.) seedlings to alkaline stress, with implications for improving crop resilience. Chickpea seedlings were subjected to combined Na2CO3 and NaHCO3 treatments, and changes in growth, root morphology, and nutrient uptake were evaluated. Alkaline stress led to substantial reductions in growth metrics (shoot and root length, fresh and dry weights), root-to-shoot ratio, and lateral root number, indicating pronounced root damage. This damage was associated with elevated hydrogen peroxide (H2O2) levels, increased membrane damage, and reduced cell viability. In response to alkaline stress, chickpea roots accumulated osmolytes (proline, soluble sugars) and upregulated antioxidant enzymes (catalase, ascorbate peroxidase) as an adaptive response to mitigate osmotic and oxidative stress. Ion homeostasis was disrupted, with decreased uptake of essential nutrients like K, P, Mn, Fe, and Zn, while the uptake of Na, Mg, and Ca increased, disturbing nutrient balance. These findings underscore the need for strategies, such as genetic improvement to enhance alkaline stress tolerance in chickpea, contributing to improved crop performance in challenging soil conditions.

The use of exclusion fencing as part of wildlife conservation programs has been increasing in recent years, particularly in Australia. Soil corrosion damage sustained on fences is a significant management concern as the weakened fence netting can provide opportunities for feral animal incursions into fenced safe havens. Soil corrosivity risk mapping can assist with the design of fenced nature reserves to reduce the frequency of fence repair and replacement. However, very little research has focused on developing methods for accurately predicting fence corrosion rates in different surface soil environments. This paper assesses the use of different soil attributes as corrosivity indicators for identifying areas of low, moderate and high fence corrosion risk in different soil environments present in South Australia (20 field sites). Zinc corrosion rates measured on zinc-aluminium fence samples (buried at sites for 9 months) ranged by a factor of nearly 50, with low rates of fence corrosion (0.1-0.7 mu m/year) observed at five sites, medium rates (0.7-2.1 mu m/year) observed at 10 sites, and extreme rates (>8.4 mu m/year) observed at four sites. Fence corrosion risk was predicted using soil pH, soil salinity and texture data, and a soil corrosivity risk index developed for use in arid soils in South Australia. Predicted zinc corrosion rates matched field observations at 45 % of field sites. The highest rates of zinc corrosion (>4.2 mu m/year) were observed at field sites with highly alkaline (pH > 8.5) and highly saline (ECe >= 5 dS/m) soils. An improved fence corrosion risk classification method, referred as the Fence Corrosion Risk Decision Tree was developed using these soil pH and salinity thresholds, which correctly predicted fence corrosion risk at 67 % of field sites at Olympic Dam and Farina and 50 % of field sites on the Yorke Peninsula. Further research is needed to assess the ability of this method to predict long-term fence damage (>2 years exposed to soil conditions).

Environmental damage attributed to nitrous oxide (N2O) emissions have received widespread attention. Agricultural sources release substantial amounts of N2O into the atmosphere. However, comparative studies on the effects of different irrigation and fertilization methods, namely, drip fertigation (a combination of fertilizing and irrigation), sprinkler fertigation, and traditional furrow irrigation with chemical fertilizer spraying, on N2O emissions in alkaline soil have been limited. Therefore, three-year in situ field observations were conducted to investigate the effect of these three irrigation and fertilization modes on N2O emissions using the static chamber method over the period 2015-2017. There are significant seasonal variations in soil N2O emission fluxes among alkaline soils under different fertilization and irrigation modes, with emissions peaking in July and August, but no significant difference in yearly variations. The N2O emission intensity of drip fertigation soil was 0.20 kg N t-1 year-1, of sprinkler fertigation soil was 0.38 kg N t-1 year-1, respectively, while of furrow irrigation was 0.91 kg N t-1 year-1, respectively. Moisture and temperature of soil were key factors driving the observed nitrous oxide variations. Compared with traditional furrow irrigation, drip and sprinkler fertigation significantly increased potato yield and decreased N2O emissions in alkaline soil, thus satisfying both yield and environmental protection.