Use Of Fertilisers On Cereals

Press, Volume CI, Issue 29832, 26 May 1962, Page 6

Use Of Fertilisers On Cereals

Drilling of icwt of superphosphate with spring-sown wheat in Canterbury was recommended by Mr C. C. McLeod, a farm advisory officer of the Department of Agriculture in Timaru, speaking to the Lincoln College farmers’ conference last week, but he said that no manure was required for autumn-sown wheat. Mr McLeod was reviewing the results of cereal manuring trials on farmers’ properties in Canterbury, Marlborough and North Otago. As a result of the 1952-56 series of trials and field observations, Mr McLeod said that the sowing of superphosphate with autumn-sown wheat in Canterbury and North Otago was considered unnecessary. In 58 trials the average increase in yield with Icwt of super compared with no manure was 0.9 bushels to the acre and where 2cwt of super was used the increase over untreated wheat was only 1.2 bushels to the acre. Where nitrogenous fertilisers were applied in this period Icwt of sulphate of ammonia drilled with the seed produced an average yield increase of 2.2 bushels and where the same weight of sulphate of ammonia was topdressed in the spring the average gain over controls was 1.8 bushels. “The trials results show that very small responses were obtained with the application of either super or sulphate of ammonia to autumnsown wheat,” concluded Mr McLeod.

An entirely different picture was, however, obtained with spring-sown crops, he explained. In spring-sown wheat large yield increases of eight to 10 bushels had been gained with the application of super. Compared with autumn-sown wheat the same differences in vigour between spring crops sown with and without super had been obtained, but

in the case of spring crops the differences were permanent and yield increases with super were usually obtained. It had been found that in spring-sown crops wheat drilled with super tillered better, had- more heads, longer and better filled ears, and gave higher yields than spring wheat drilled without manure.

“The main reason for the differences between autumn and spring-sown wheat responses to super appears to be the time the crop is in the ground,” he said. “In the case of autumn-sown wheat its growth period is usually four to five months longer than that of spring-sown wheat. This time lag appears to allow unmanured autumnsown crops to catch up with crops drilled with super.”

Use of nitrogenous manures on autumn and spring-sown crops was only recommended at Icwt to the acre if they were yellow and unthrifty in September. Mr McLeod’s recommendation for spring-sown malting barley was for the drilling of 1 to Itfccwt of super with the seed. Discussing the results of trials in Marlborough, Canterbury and North Otago between 1958 and 1961 he said that Icwt of super gave an average increase in yield of seven bushels while 2cwt of super gave only two additional bushels. Super with barley resulted in more rapid establishment, increased vigour and leafiness compared with no manure, and this difference usually remained until harvest, but because of Marlborough, Canterbury and North Otago’s fairly low summer rainfall barley usually could not utilise heavy dressings of phosphatic manure. The topdressing of nitrogenous manure on barely caused delay in maturity, quite frequently lodging and difficult harvesting and reduced

yields. In addition it could increase the nitrogen content of the seed to a level which affected its malting quality. For spring-sown oats for milling the recommendation was to use 1 to Hi cwt of super at drilling. Trials had given yield increases of eight to 10 bushels to the acre with Icwt of super compared with no manure, with very slight increases in yield with more than 1 to of super and delayed maturity, lodging, difficult harvesting and frequently reduced yields with nitrogen application.