Energy and carbon accounting case study on Keytah (NEC0901)

Energy and carbon accounting case study on Keytah (NEC0901)

Keytah is an irrigated cotton and grains farming operation west of Moree in Northern NSW. The total area of the property is 24000 hectares of which 10400 hectares is irrigated cotton, grown in rotation with wheat. During a normal season only half of the irrigated area is cropped at any one time with the other half maintained as a bare fallow. The farming system includes a summer cotton crop, planted in October and followed by a winter wheat crop planted in May and harvested in November. After the winter wheat crop a fallow of approximately 12 months takes place before cotton is replanted back in October. The farming system incorporates 60 inch beds where cotton is usually grown in two rows 30 inches apart or more recently in a single row where water supplies are limiting. In comparison the wheat is grown in 4 rows on the same 60 inch beds at a spacing of 15 inches. Regardless of the planting system adopted different plant lines are maintained between the summer and winter crop options. All tractors have been extended to operate on 120 inches (i.e. 3 m) centres. In a normal irrigation season Keytah relies on 7 to 7.5 ML/Ha of water for irrigation which is applied by surface (furrow) irrigation and two lateral move irrigators. Water is sourced from the Gwydir and Mehi Rivers and is pumped into on farm storages before being distributed to the field for irrigation. In response to limited irrigation supplies (1 ML/Ha) in 2007/2008, a radical change in farming practices is currently being pursued to establish and produce a cotton crop. Previously the variation in soil properties across the farm has been identified via an EM survey. This survey was conducted when the soil was relatively close to field capacity. In an attempt to identify fields which had adequate soil moisture for planting cotton, an EM survey of the farm was again conducted to identify areas of high soil moisture content. The EM survey identified 2 fields side by side where one field had an estimated increase in soil moisture of 40% soil moisture. This increase in soil moisture was attributed to no tillage over the fallow period.

Material from this publication may not be used unless prior written approval has been obtained from the National Centre for Engineering in Agriculture and the Cotton Research and Development Corporation (CRDC).
NCEA Publication 1003254/1.