Farming Column

Opunake Times, 19 August 1932, Page 1

Farming Column

MANURING PASTURES IMPORTANCE OF NITROGEN EARLY AND BETTER GRASS During the past three years a jrood deal of interest has been taken by pastoralists in the use of a nitrogenous manure, such as sulphate of ammonia, used along with phosphate, as an aid to getting production from grassland in New Zealand. Experimental work on the Continent and in England indicates that pastures treated with nitrogen as well as phosphate give a greater return than those treated with phosphate alone. Trials were put down in various parts of New Zealand and hundreds of farmers tried out the nitrogenous feritlisers —in a large number of cases with considerable siiccess. In others, however, the results were somewhat disappointing, but, after three years' experience, a good deal lias been learnt as to where, how, and when to apply nitrogen on grassland. Difference in Grasses. It is only within the last three years that there has been a full appreciation of the difference in types of ryegrass in New Zealand. It is now known that the false perennial type of ryegrass will not persist no matter what the fertilising practice is. Unfortunately, a good quantity of nitrogenous manure was applied to this type of ryegrass, with disappointing results. In its first year the ryegrass could be stimulated and greater growth "out of season," and for ensilage and hay, procured, but after this the ryegrass gradually ran out, even where phosphate only had been applied. Experiences of hundreds of farmers, however, have shown that on true perennial ryegrass—e.g., Hawke's Bay type —nitrogen, used along with phosphate, markedly increases the vigour of the plant, giving a greater yield of pasturage and also enabling grassland to produce more "out-6f-season" grass. Most of the farmers who are sowing down Hawke's Bay ryegrass now use nitrogen along with phosphates, firstly to get good early establishment and later on in order to maintain a good sward. A good deal of nitrogenous manure such as sulphate of ammonia has also been applied to pastures mostly of the brown-top type, and others that were weak and open, many of them poor in clover, and on such grassland types nitrogenous manuring is, in the main, not economical. Fortunately a wide area of Taranaki has been sown with good perennial ryegrass, and so most farmers can use nitrogen profitably. Nitrogen and Phosphates.

While it Las always been stressed that nitrogen has to be used on pastures adequately phosphated, still it is very difficult tr decide just what adequate phosphating implies. For instance, where phosphate is applied in the autumn and sulphate of ammonia used in July or August, there is every likelihood that most of the phosphate has been used up in the grass and clover and some of it locked up in an insoluble form in the soil, so that by the time the nitrogen is applied there is very little available phosphate in the soil. For this reason some farmers have experienced a kind of slumping of the pasture after the nitrogen has been applied. This seems to be due solely to the fact that the phosphate supply to the plant is insufficient. Where farmers used phosphate along with nitrogen at the time of application, first-class results have been obtained. This is one reason why ammoniated super (two parts super to 1 part sulphate of ammonia) has become such a popular manure in the last two years. Where farmers have had experience of pastures getting a dry appearance after the sulphate of ammonia has acted, they would do well to always appl" a certain amount oi phosphate alone with each application of nitrogen. Wrong Amounts of Nitrogen. Disappointing results have come in in some instances from flip use of wrong quantities of sulphate of ammonia. There are instances where up to five cwt of sulphate of ammonia per acre has been used in one application, this amount being far in excess of what is desirable. On suitable pastures—good land, where the phosphate supply is sufficient, two cwt can be used, but, in ordinary instances, not more than 1 to IK cwt of sulphate of ammonia per acre should be applied for dairy pastures at one time, and about two-thirds of this amount for sheep pastures. Other cases are recorded where insufficient amounts were used, say not over half a hundredweight, which is much too small a quantity over an acre to be effective. Time of Application. Nitrogen is much more dependent for its effect on time of application than, for instance, is

the case with phosphates. For instance, if it is applied in the "dead" of winter, it is liable to be locked up with the organic matter of soil and then not become available until the bacterial activity in the spring makes it available for plants. For earlv spring frass it is important to use nitrogen when the plant is beginning to make movement in the soil, although there may not be much top growth appearent. This period is usually July in most parts of New Zealand, but may not be until September in the southern parts of the South Island. Of course, on sheltered paddocks applications could be made earlier than on sheltered.

In order to grow grass in July> farmers found it best to apply nitrogen in earlv May, grow the grass in May and hold it for June and feed it in July, missing out June applications except on sheltered paddocks, then applying nitrogen to another paddock in July for August growth and again at the end of July for early grass in late August and early September. Generally speaking, there is not much grass available for dairy cows until the middle of September even in the Waikato. This year a large number of Waikato farmers are applying nitrogen with phosphates at this time of the year. After Management.

A good deal has been learnt in the past two years as to the best way to manage pastures treated with nitrogen. In the main, it is important to exercise greater control over nitrogen-treated grass than with grass treated with phosphate only. For instance, on light land, if nitrogen is used in July to get early grass* pastures should be grazed from them onwards. On what may be termed medium dairy land, the early grass can be used for early grazing, then a crop of ensilage taken at the leafy stage and the pasture then grazed. Farmers find that it is a good practice to apply say, two hundredweight of superphosphate to such pastures immediately the ensilage crop is taken off. This helps the pasture, not only nitrogen-treated, but others also, over the dry summer period. Where many farmers went wrong in the first year's use of sulphate of ammonia, was in allowing the pasture treated with nitrogen for early grass to go for hay after the first grazings. This is wholly undesirable as the nitrogen is growing the grass away from its phosphate supply and the pasture is likely to be open afterwards. There are now hundreds of farmers scattered throughout New Zealand who have found out the way to use nitrogen wisely with marked benefit to themselves. There is nothing mysterious about the use of nitrogen on grassland, but it wants a little more understanding than is the case with phosphates. Value of Early Calving.

However, it has been pointed out time and again, and as farmers appreciate, it is most important to bring cows in early ii good producing season is to be secured, but it is no good calving early unless there is sufficient feed of the right type. It has now been demonstrated that nothing brings cows to the flush as quickly as early spring grass, produced by the wise use of nitrogen along with phosphates. Apart from the getting of grass "out of season," which is so valuable both to the dairy-farmer and to the sheepfarmer (because early lambs, particularly lambs fat off the mother, give the greatest profit), the use of nitrogen along with phosphates .has been proved to greatly improve pastures by increasing the ryegrass content and lessening the incidence of weeds. Too much clover in a pasture is undesirable because it is clover that gives rise to bloating (a serious trouble in many districts), and after all clover is a very short season producer, starting late in the spring and going off early in the autumn. It is ryegrass that gives feed in autumn, early winter and early spring, and, throughout most parts of New Zealand, pastures can do with an improvement in their ryegrass content. The proper use of nitrogen increases ryegrass content and keeps up a proper balance of clovers. (To be continued).