Procedures For Pasture Renovation

Press, Volume CIX, Issue 32221, 13 February 1970, Page 6

Procedures For Pasture Renovation

With the frequent rains that most districts in Canterbury have been receiving in recent weeks, soil conditions are ideal for resowing to new’ pasture. While many farmers will be cultivating for pasture renewal, it will obviously not be possible to treat all the affected pastures in this manner. For several years now many farmers have been successfully resowing to grass, with and without cereals, by using drills adapted for direct seeding or overdrilling without cultivation.

This article summarises the several methods that may be used and includes the latest technical advances for this relatively low cost method of improving pasture production. Farmers should begin planning now their renovation programme for this autumn. The most suitable months for this work are February and March, but the work may be extended into April to provide feed for early spring. Best results will be obtained on pastures that are either clover dominant or showing a high percentage of bare soil. Where low fertility grasses or any grasses are dominant, farmers would be wise to con-

sider spraying with Paraquat to eliminate competition between new grass seedlings and established grasses. Farmers should inspect pastures to be treated for insect pests, grass grub, porina, and particularly stem weevil, as the presence of the latter pest will determine the most suitable grass to sow since no reliable form of control has yet been found for this pasture pest. If the presence of stem weevil is identified, then the only grasses to sow are Ariki ryegrass, perennial ryegrass, cocksfoot and prairie grass. All other ryegrasses are susceptible.

Preparation: If paddocks are not already bare, graze hard with a concentrated mob of sheep, or on a dairy farm trim the paddock bare with a closely set forage harvester. The more growth that is present at the time of drilling the poorer the establishment of new grass will be. In general, drill after rain or irrigation, and following sowing it is often a good practice to maintain grazing pressure for a further seven to 10 days until germination of new grasses or cereals has taken place.

The recipe for success is: Select clover dominant er bare pastures, or lucerne. If grass weeds are present,

Fertility Level N. Lb High 15-25 Medium .., 25-35 Low 35-50 spray with a suitable grass weedkiller (one to two pints of Paraquat plus sticker per acre is recommended). Use suitable equipment. The Duncan seedliner drill fitted with overdrilling points and. where necessary, skeiths has given consistently good results. Disc seeders are suitable for light sandy soils or stubble paddocks. The new disc seeder capable of injecting liquid nitrogen and solid fertiliser and seed has given satisfactory results on all soils, with the exception of very stony paddocks.

Use good seed—quick germinating seed is vital and only high quality grasses or cereal seed should be used. Pest control—avoid surface renovating pastures affected by grass grub, porina or stem weevil. For the first two pests satisfactory control may be obtained for this autumn only by the use of D.D.T. super at If cwt per acre broadcast prior to drilling. This applies to sheep and cropping farms only up until June 30, after which further use of this product has been banned.

Seeding rates of grasses are:

Tama ryegrass Poroa ryegrass (Ital.) .. .. Manawa ryegrass (short rot.) Ariki ryegrass (long rot.) Cocksfoot Prairie grass Eor cereals the rates are: C.R.D. ryecorn Amuri oats Arawa wheat Greenfeed barley A few ounces of turnips or rape seed may be sown with a grass and clover mixture, but their inclusion is not recommended where cereals and grass are sown together. Soil and Fertiliser: Where previous liming history is not known, a soil test for pH (degree of acidity) should be arranged through our K.P. technical staff or the farm advisory division, Department of Agriculture. During or immediately after overdrilling it is often: desirable to cover the |

grooves made by the drill I with chain harrow’s. and: where soils are soft and] spongy to use a roller. Nitrogen and phosphorous must: always be drilled in close! proximity to the seed to! ensure a quick uniform strike and provide sufficient plant food until the following spring.

In those areas where potassium is required, it should be applied separately as 30 per cent potash super. Both molybdic and sulphur fortified super may also be ap-i plied separately. The following table gives; a broad indication of the amounts of nitrogen and phosphorus required per acre at three different fertility levels:—

Approx. Equiv. j P. Lb in D.A.P. 10-20 1 cwt 30-40 11-2 cwt 40-50 2-2 j cwt

The choice of materials will depend on the cost per ; lb of nutrient applied as well as agronomic and phy-i steal advantages. Granulated compound fertilisers, which are highly soluble. How and store well, and are preferred to the powder ammoniated mixtures. D.A.P. (di-ammonium phosphate) 18-20-0 has proved to be an excellent fertiliser for many purposes, including overdrilling with grasses and/or cereals. For farmers who, for reasons of personal preference, still wish to use powder fertiliser. then ammonia super 2/1 (7-6-0) at 3 to 4cwt per acre is recommended. If insecticides have been] used the prescribed with-i holding periods must be observed. Farmers should ensure that they carry the extra stock necessary to profitably and*, efficiently utilise the extra! feed grown. When feeding the resul-j tant growth a farmer should allow about 10 to 121 b greenfeed and a Hb hay per ewe each day. For a 100-day winter you w’ill need from 2j to 5 acres of greenfeed for 100 ewes, or a t to 1 acre of greenfeed for each milking cow. Alone With Cereal lb per acre lb per acre 25-30 10-15 15-20 10 15-20 10 20 , 10-15 3-5 10-15 Alone bus. bus. per acre per acre With grass 2 U 3-4 11-2 2-3 i-lj 2-3 1-1 i

The writer of the accompanying article on the renovation of droughtaffected pastures is Mr D. J. G. Davies, field research officer of Kempthorne Prosser and Company, Ltd