FARM SCHOOL.

Hokitika Guardian, 20 May 1926, Page 1

FARM SCHOOL.

SESSION AT ASHBURTON. s CROP ROTATION AND MANURES, f ASHBURTON, May 18. Ilx> Ia rm school uner tlie auspices 1 of the Department of Agriculture was ; opened at the High School to-day, when lectures were given by Mr A. • IT. Cockayne on crop rotation and on , the composition of manures. Mr A. J. Ferguson also delivered a lecture this evening. There was an attend- . ance of twenty. After tracing the progress made in the utilisation of crop rotations, Mr Cockayne said it was the introduction of a stock food into the rotation of crops that led to the development of the Norfolk four-course rotation. This rotation consisted of a cereal, followed by a root crop, followed by a springsown cereal, followed by a clover crop lasting for one year. A complete fallow IV as thereby'''avoided, stock food was introduced, and the ground was brought again into somewhat the same condition as when the rotation was. commenced. Proceeding, Mr Cockayne dealt with the matter of cultivation charges, stressing the value of the employment of tractors on considerable areas of Canterbury lands. Dealing with manures, the lecturer said that there was nothing that had increased more in use during the past fifteen years or so than artificial manure. In 1900 New Zealand imported about 25,000 tons, and about 13,000 was represented by bone-dust. At the present time the amount used stood at 200,000 tons, and of this amount about 150,000 tons wore used for topdressing and 50.000 for annual crop production. Almost all the manure used at the present time was of a phnsphatic nature, about 100,000 tons being represented by superphosphate, and about 50.000 tons by basic slag. Superphosphate and basic slag represented the two most important phosphatic manures used. In addition there were a number of mixtures of superphosphate and rock phosphate, with a certain amount of lime incorporate sold with the term basic prefixed. Somewhere about 40,000 tons of the total amount of manure used was of this type of phosphate. Regarding the charges for phosphatic manures, farmers were sometimes at a loss to understand the phosphate was sold in various grades, and the meaning of a 44-46 super was that for every 3001 b. there was somewhere between 441 b. and 461 b. of the equivalent of phosphate and lime. In the ease of the content being stat- • ed in phosphoric acid, the figure supplied had to he multiplied by 2.2 to bring the content to the equivalent of phosphate of lime. Basic slag sold at 17-20 meant that it contained 171 b. to 201 b. of phosphoric acid. In point of fact, as far as fertilising manures were concerned, 17-20 basic slag contained about the same equivalent of phosphate of lime as 40-20 superphosphate, although one might not be of any use in a. dry climate, while the other might be exceedingly useful. Concerning the rock phosphates used in New Zealand, Mr Cockayne said that the fertiliser from Ocean Island contained up to 871 b. of phosphate of lime in every 1001 b. of the material purchased. Speaking of the sale of , the various grades of superphosphate, the lecturer said that the position would soon arise in the North Island when only the 44-46 grade would be available. In order to avoid the expense of filling, it suited the manufacturer better to produce only the higher grade. . In the past the manufacturer had sold 36 super because the farmer, who thought it was the cheaper proposition, demanded it. In the nitrogen manures, there was a very wide range of nitrogen content. Nitrogen was the most expensive ingredient to purchase, and, seeing that it was easy to grow leguminous plants in New Zealand, it seemed easier to obtain nitrogen through tlie plant medium. In conclusion, Mr Cockayne said that efforts were being made to force the fertiliser manufacturers to provide a chemical and mechanical analysis of the material sold.