Rice yields a matter of nitrogen, sowing time and a bit of luck

Ricecheck fertiliser recommendations, time and luck, were the crucial factors linked to high yields of the 2004 rice growing season.

Chairman of the Irrigated Research and Extension Committee, Peter Draper, said a recent meeting of Murrumbidgee and Coleambally rice growers identified a number of factors responsible for achieving yields of up to 12 tonnes per hectare.

"The most important factor linked to high yields was low nitrogen from low paddock fertility, or lower nitrogen fertiliser rates before sowing," he said.

Growers' findings in the paddock reflected well on Ricecheck recommendations for nitrogen application, NSW Agriculture's technical specialist for irrigated farming systems, John Lacy, said

"This year a number of crops were over fertilised, resulting in yields as low as three tonnes per hectare," he said

"It is vital to have optimum fertility before planting as nitrogen levels that are too low or too high can shatter yields.

"Low yields were exacerbated this season - cold damage is made worse by high nitrogen levels and low water depth."

Mr Lacy said the NIR Tissue Test was the best way of evaluating the level of crop nitrogen and was far more accurate than visual assessment.

"Being misled on nitrogen application requirements in a year like this one has cost some growers a lot of money," he said.

"But for other growers late or very early sown crops realised increased yields."

Mr Lacy said the cold sensitive microspore stage for the late crops occurred after the cold nights from mid to late January.

"The microspore stage for normal sowing times coincided with the cold period leading to higher grain sterility and low yields," he said.

"Some growers delayed sowing because of uncertainty with water allocations, not knowing whether they had enough water to grow rice. In fact, some growers at the meeting said it was pure luck they missed the cold.

"Late sowing yields were a one off and growers needed to stick to normal early sowing next season."

Media Contacts: John Lacy 69512 738, 0427 311 425 or Brett Fifield 6391 3311, 0427 029 511