The aim of this research was to improve nitrogen use in irrigated cotton by looking at how farmers around the world are improving Nitrogen Use Efficiency (NUE), and to identify what management tools and practices farmers are implementing to improve NUE. To achieve this research was carried out in England, USA and Japan.

The research undertaken overseas highlighted that farmers have implemented rotations and cover crops to improve NUE. Rotations are being used to increase the amount of mineral nitrogen in the soil through planting legume crops that fix nitrogen in the soil. Cover crops are being used to provide ground cover for the soil surface, to improve water infiltration, improve water holding capacity, and reduce leaching and runoff.

Farmers overseas have introduced new irrigation techniques to improve Water Use Efficiency (WUE) and reduce waterlogging, which in turn improves NUE. Farmers have moved away from flood irrigation and have introduced overhead sprinkler irrigators, in which Australian cotton growers have been slow to adopt.

Research undertaken in USA and England showed that both dryland and irrigated farmers have introduced no till farming practices. While in Australia dryland farmers have adopted no till farming practices, irrigated cotton growers have not introduced these practices and still use excessive tillage as a farming practice. No till farms in the USA and England illustrate the benefits of no till outweigh the conventional tillage practices.

The adoption of Precision Agriculture (PA) has been much faster overseas compared with Australia. Famers are using a number of PA practices including imagery and real time soil testing to improve NUE through the introduction of Variable Rate Technology (VRT). Farmers are using NVDI imagery from satellites and drones to create management zones across the fields. Farmers are able to apply different rates of fertiliser through VRT, which has not been widely used by Australian cotton farmers.