414 THE FARMERS HANDBOOK. 



Manuring. 



.Maize is one of those crops that make great demands on the plant-food 

 •in the soil. Tt has been estimated that a 50-bushel crop of maize removes 

 from the soil approximately 75 lb. of nitrogen, 30 lb. of phosphoric acid, 

 and 50 lb. of potash. On very heavily manured fields of small area in 

 the United States of America, yields of up to 255 bushels per acre have 

 1) en produced. This is rather valuable evidence that it is impossible to have 

 the soil too rich for maize— a remark that cannot be made of many other 

 •crops. Although good cultivation to a large extent unlocks the store of plant- 

 food present in the soil, we are beginning to see, on our well cultivated 

 alluvial soils, increasing evidence of diminishing maize yields compared with 

 those of twenty years ago. This is surely a sign of failing fertility. We have 

 onlv to consider how the yields of maize are suddenly increased on " worn-out " 

 laud which has been sown to pasture for a few years, and how comparatively 

 good crops are produced on some virgin soils for only a year or two, 

 to realise what is lacking. Undoubtedly it is humus, or decayed organic 

 matter, without which the soil richest in mineral constituents may become 

 quite poor. The retention of moisture by the addition of humus to the soil, 

 .together with good cultivation, will do much to explode the idea that maize 

 must have rain at the tasselling stage in order to produce a successful crop. 

 In America, where the conditions necessitate the housing of cattle in the 

 winter, organic matter can be supplied to the soil in a cheap and excellent 

 form, in the shape of farmyard manure. Wherever it is possible to obtain 

 farmyard manure by any means under our conditions it should most certainly 

 be applied. To supply that valuable ingredient, humus, it will be found 

 necessary, under most conditions here, to resort to ploughing-in or feeding off 

 green crops, particularly legumes. The most suitable for our maize districts are 

 velvet beans, co wpeas, field peas, vetches, and the clovers. Besides supplying 

 humus, such crops as these gather nitrogen from a cheap source — the 

 atmosphere— and fix it in the soil. This element is removed by the maize 

 crop from the soil in large amounts, and is the most expensive element 

 purchased in the form of chemical fertilisers. Indeed, it seems that the 

 application of readily-soluble nitrogenous fertilisers to maize is likely to have 

 the effect of promoting a soft and sappy growth, to which a dry spell in the 

 later stages is particularly injurious. 



Experiments with fertilisers have been carried out for several year-. 

 by the Department on all classes of maize soils in different districts, 

 and the results point conclusively to the decided profitableness. of artificial 

 fertilisers in certain ^quantities and mixtures for different districts even on 

 some of the best soils where high yields are still obtained. For instance, on 

 the coastal' alluvial soils, in several cases yields of 80 or 90 bushels per acre 

 without fertilisers have been increased another 10 bushels or so by the use 

 of a moderate quantity of fertiliser of the right kind. 



The question of what kind of fertiliser or which mixture is a very 

 important one, as in some cases fertilisers have been found to diminish the 

 yields. For instance, on the coast the application of a mixture containing 

 easily soluble nitrogenous fertilisers, such as sulphate of ammonia or nitrate 

 of soda, has been found to decrease the yield by 2 or 3 bushels per acre, 

 which, with the cost of the fertiliser, has resulted in a loss of about 30s, 

 per acre. On the other hand, on the coast the application of 2 cwt. per 

 acre of a mixture, consisting of equal parts of superphosphate and bonedust, 

 has given an average increase of 9 bushels per acre, thus showing a profit of 

 about 30s. per acre after the tost of the fertiliser has been allowed for. 



