NGN - Understanding the nitrogen contribution of chickpea in Queensland using the natural abundance technique

A range of summer and winter pulse crops are widely grown in the Northern Region for the benefits they provide in the crop rotation including improved nitrogen (N) nutrition, weed and disease management. While the perception has been that legumes benefit the rotation by contributing atmospherically fixed N to subsequent crops, the magnitude of this is questionable and not well understood. When soil N is available, pulses can become 'lazy' and utilise soil N reserves rather than fixing their own N. In addition, as growers have become better at growing pulses, harvest index has increased, and significant quantities of N are exported off the paddock in harvested grain.

This investment will seek to quantify the N contribution of chickpea in the key production areas of Queensland using the natural abundance technique. Data collected in field work should support the delivery of an extension program aimed to increase growers confidence in understanding how soil and plant parameters impact the amount of N likely to be fixed by chickpea. This knowledge will encourage growers to look at crop sequencing and N fertiliser strategies across the farming systems with fresh eyes.