Review of crop-specific tolerance limits to acidity, salinity, and sodicity for seventeen cereal, pulse, and oilseed crops common to rainfed subtropical cropping systems

Soil constraints limit crop water and nutrient extraction and lead to yield loss globally. In rainfed agriculture, the selection of crop species more likely to yield well under constrained conditions is an important management tool. However, information on the most appropriate crops is often difficult to access due to its publication in a wide range of disparate sources and the various measures of crop tolerance used. This study aimed to improve our ability to identify crops for constrained areas in rainfed subtropical cropping systems by compiling published information that had assessed the grain yield response to acidic, saline, or sodic conditions of 17 cereal, pulse, and oilseed crops. This information was used to develop a 'traffic light' system for salinity and acidity to provide guidance on when soil pH or the electrical conductivity of a saturated soil extract (ECe) is likely to be 'good', 'potentially limiting', or 'poor' for grain yield. Crops were also ranked according to their likely ability to yield well under saline, acidic, or sodic conditions. For all crops, the point at which grain yield was affected by soil constraints was variable and there was often only a small amount of published information available to help guide the identification of tolerance limits and rankings, particularly for sodicity. Many studies were also conducted under experimental conditions that differed from rainfed farming, which can affect the transferability of results. Confidence in the tolerance limits and rankings is thus only moderate and further work is required to confirm their applicability.

Automated summary

Soil constraints globally limit crop water and nutrient extraction, leading to yield loss. This study aimed to compile published information on crop responses to acidic, saline, or sodic conditions to identify crops suitable for constrained areas in rainfed subtropical cropping systems. Results show that tolerance limits and rankings vary among crops, highlighting the need for further research to confirm their applicability.