Pasture Establishment on Marine Silts

New Zealand Journal of Agriculture, Volume 66, Issue 4, 15 April 1943, Page 224

Pasture Establishment on Marine Silts

Pasture establishment has been prominently before the farming community during the past twenty years. Many theories and innovations have been advanced from time to time, only to be subsequently rejected

through some weaknesses in their practical application. Out of the controversy that undoubtedly existed there has been evolved a procedure in laying down pasture that has a wide application throughout the country.

By

C. WALKER,

Instructor in Agriculture, Thames.

IT is seldom ‘ that a progressive farmer will attempt to grass an area without thorough initial preparaparation, though a decade ago it was not uncommon to find an excellent mixture being sown under quite adverse conditions of soil cultivation. Likewise, the farmer of today, through experience, has learned the wisdom of seeing that his mixture consists of only the best quality seed. Fertiliser will be used, so far as it is permitted' by rationing, to ensure the greatest advantage to the young grass crop. , These points are undoubtedly of paramount importance in any work involving the establishment of grass; they are basic principles that are generally applicable to a wide variety of soil and climatic conditions., While this article is devoted . primarily to the ■ question of grassing marine silts, the . general procedure will be much the same on other, classes of land? Naturally, there will be variations in seed mixtures, in manurial treatment, and perhaps to . some extent in cultivation.

Preparation of Area

The area to be selected on the average farm is usually one which has already been in crop, or which is in inferior pasture or natural growth. If it has not already been ploughed, this work. should not be delayed any further unless, of course, where it has baked too hard to permit ploughing. If this is so the first opportunity after softening rains should be taken to get the soil broken up. .If ploughing is possible, when the work has been done the area should be immediately disced down, fined down further with a clod crusher, and harrowed. The aim should be to get as fine a seed bed as possible well in advance of actual sowing.

Weed Growth

At this time of the year there will most certainly be a pronounced growth of seedling weeds following this cultivation. These will have to be dealt with from time to time by periodical discings and harrowings. It is not pos-

sible to indicate just how often this would need to be done, as much depends upon the weather conditions. In showery weather more seedings will appear than under hot, dry conditions. A certain amount of judgment will therefore be necessary to decide upon the frequency of this work; but the aim should be to. thoroughly suppress all weed growth as it appears. By so doing, the subsequent young grass crop will obtain an excellent start without the fierce competition that weeds are capable of exerting. If weeds are permitted to flourish they soon overrun a newly-sown grass area, with the result that the pasture never fills out properly. Just prior to sowing, which should take place as early in March as possible, the seed-bed should be harrowed and rolled, so as to give fineness and firmness, both of which lead to an excellent “strike.”

Seed Mixture

Farmers possess quite .varied opinions on what should constitute a seed mixture for this class of country. All give ryegrass a prominent place. Some favour paspalum, while others would exclude it at all costs. Some like a fair amount of cocksfoot, while others lean towards timothy and even foxtail. On the whole, the pastures sown in the past are good; but this may not be entirely due : to the mixtures sown. There is a tendency for certain species to become dominant under conditions which suit them. Thus foxtail will thrive under damp conditions, prairie grass under light grazing, danthonia on poor country, and ryegrasses under heavy stocking. " On the Hauraki marine silts, stocking has been heavy, so that there has been a tendency under good management for ryegrasses

to dominate the swards. Timothy, and cocksfoot are also prominent in the better pastures, while on the weaker pastures browntop and creeping bent are by no means uncommon. One of the problems on this country since its development has been that of successfully establishing clovers. In conformity with general practice on other good soil types, the first efforts at clover establishment aimed at getting white clover and red clover into the swards. Unfortunately these efforts failed, and, as is common where clovers fail, the grass species lost vigour, and the pastures became quite unproductive.. The reason for this clover defection can be found by a study of the history of these soils. At one time they formed the ocean bed as an . extension of the Hauraki Gulf, and during that time became impregnated with saline material. Neither white clover nor red clover will tolerate a very high degree of soil salinity, and therefore, in these soils, they quickly died off, leaving only grass species. The ryegrasses, although tolerant of salt to a certain degree, remained alive but considerably stunted through a lack of nitrogen as supplied by vigorous clovers. It

was then found necessary to introduce strawberry clover in order to induce , grass growth, with the result that the pastures today rank in quality with any to be found throughout the Dominion. : ; ' . Any grass mixture for these marine silts should include a liberal' sowing of ryegrasses and some strawberry clover. Other species may be added according to personal inclinations; but the following would constitute an excellent sowing: Perennial ryegrass .. 25 lb. . Cocksfoot 5, .. . . 8 lb. Timothy . . .. 2 lb. White clover .. . . 1 lb. Strawberry clover . . 2 lb. Paspalum .. .. 6 lb. 44 lb. per acre.

There will undoubtedly be some who disagree with the inclusion of paspalum, but, under proper control, it is an excellent butterfat producer in the summer and late autumn. Moreover it will thrive in association with other grasses without subduing them if it is kept in control. There may be an objection to having it over the whole farm, but it may be convenient for a few fields on every farm where it could be included. In setting out the foreging mixture reference to seed quality has purposely been omitted; but wherever a variety is mentioned an effort should be made to get the best strains of that variety. Where the variety is certified this will be a sufficient guarantee of quality, and it should be insisted upon.

Manurial Treatment

Few farmers today require to be reminded of the value of adequately manuring the young grass crop. This is a more important function than the annual topdressing of an old sward.

Unfortunately we are not in a position at present to use as much fertiliser as would be desired, but every effort should be made to sow some phosphate with a young grass crop. Even on the marine silt where topdressing is normally regarded as superfluous, it is essential to get some manure to the young pasture. Phosphates in particular are important in establishing rooting systems, and a good root system is the foundation of any pasture plant. On the Hauraki marine silts, therefore, up to 2 cwt. per acre with about 5 cwt. lime as the initial topdressing is suggested.

While this article deals primarily with establishment it would not be out of place to mention two points in the early life of a pasture that require watching. Firstly, the farmer concerned should not be in too great a hurry to graze it for the first few times, When it appears to be getting away bite it back a little with light stock. Secondly, do not be tempted to make hay or save seed ,in the first year. This opens the sward at the time when one should be concentrating on securing dense establishment.