Seeding Rates for Pastures on Ploughable Land in Auckland Province

New Zealand Journal of Agriculture, Volume 81, Issue 2, 15 August 1950, Page 113

Seeding Rates for Pastures on Ploughable Land in Auckland Province

By

J. E. BELL,

Fields

Superintendent, Department of Agriculture, Auckland.

FARMERS sowing down pastures frequently consult officers of the Extension Division not only about the choice of species but about quantity to sow. The advice given has been based on general experience, and experiments laid down have indicated this to be a very reliable guide. The seeds mixtures recommended in this article are for the general type of ploughable soils in the Auckland Province after thorough cultivation has been done and where adequate lime and fertiliser have been applied. THE trials on which mixtures are based have been laid down on varying soil types under different management and so give a fairly good cross-section of results which might be obtained on farms. The only objection which might be raised is that in the trials the palatable species often suffered by being more severely grazed than they would be normally if sown in a paddock on their own or in a mixture. The following outlines the results of the different rates of seeding of the various species the sowings of which were studied. Perennial Ryegrass Sowings of 10, 15, 25, and 451 b. per acre of. perennial ryegrass were made with 11b. and 31b. of white clover with and without other species. Where conditions were poor for establishment up to 451 b. was needed, but where the seed-bed was properly prepared and weather conditions following sowing reasonable 251 b. produced a satisfactory cover. Fields Instructors of the Department of Agriculture have usually recommended about 251 b. of perennial ryegrass. In the early stages sowings of 101 b. and 151 b. were definitely unsatisfactory and the cover was in proportion to the amount sown. Thus in a trial where 251 b. produced a good cover, 101 b. produced about twofifths, and 151 b. three-fifths of that cover during the first year: The estimated loss of grazing in the first year on the lightly seeded areas much more than covered the extra cost of seed where 251 b. per acre was used. In 2 or 3 years the. lighter sowings catch up with the heavier sowings. Perennial ryegrass, because it is a hardy plant under high fertility and stock grazing and because it establishes quickly, is the farmer’s best weapon for preventing ingress to the sward of undesirable plants such as browntop and flat weeds. In one trial at Wark worth, sown down in the autumn of 1947 on land liable to browntop in-

vasion, it was found that with seeds mixtures containing 101 b. and 201 b. of perennial ryegrass browntop invasion was rapid and fairly extensive. Where the mixture contained 401 b. of perennial ryegrass little browntop became established. Unfortunately this principle applies also in regard to desirable species, which may be paspalum, cocksfoot, or timothy. Trials show that ryegrass prevents these grasses from establishing, and with paspalum the amount sown affects the degree of establishment.

The table above, compiled from one of the trials with different sowings of ryegrass and paspalum, shows the effect on paspalum . and volunteer browntop establishment. The figures relate to the density of paspalum and browntop 2 years after sowing, 0 showing none present and 10 a very high degree of cover of the particular species.

The only contradiction is plot 13 where the invasion of browntop was not as great as would be expected. There were many flat weeds in this plot, which may have inhibited browntop invasion to some extent. It will be noted that the paspalum strike was not inhibited until 401 b. of perennial ryegrass was sown. Later when paspalum becomes properly established the trial will reveal the effect of its establishment on volunteer browntop. It can be seen that the determining factors in the ultimate sward are complicated, species having different effects on each other. It is possible that in plots where the seeding rates of ryegrass were low and the ingress of paspalum consequently was earlier there may be less browntop, contrary to the early results from the trial. Short-rotation Ryegrass In trials varying rates per acre of short-rotation and perennial ryegrass were sown as follows, with 21b. of white clover: :

SEEDING RATES FOR PASTURES ON PLOUGHABLE LAND IN AUCKLAND

In most of the trials the area surrounding the trial was sown with perennial ryegrass as the predominant . species; consequently, because of its palatability, the short-rotation ryegrass in the plots was punished by stock and its chance of recovery in the next season diminished. In the first year . greatest production was obtained where short-rotation ryegrass was sown alone with white clover at 251 b. to 351 b. per acre. In the mixtures of perennial ryegrass and short-rotation ryegrass the proportions of each which it is advisable to use depend on the recovery of short-rotation ryegrass. If short-rotation ryegrass fails to recover, sowings of it should not exceed 101 b. per acre, and probably a mixture containing 251 b. of perennial ryegrass and 51b. of short-rotation ryegrass will be most satisfactory. Where the shortrotation ryegrass recovers very well a sowing of 151 b. of short-rotation ryegrass and 151 b. of perennial ryegrass will be most satisfactory. Between the extremes a sowing of 201 b. of perennial ryegrass and 101 b. of short-rotation ryegrass would be advisable. To be persistent and to last several vears oe persistent ana to last several years or to be permanent, short-rota-t 1 ? 1 ? , ryegrass , requires a fertile soil V m moist m summer yet reasonably well drained in winter, and grazing should not be severe, particularly in late spring and early summer. x Corkfont \xqgkstoot Cocksfoot at 5, 10, 15, and 201 b. per acre was sown with 151 b. of ryegrass and 21b. of white clover per acre, and cocksfoot at 101 b. per acre was sown without perennial ryegrass and with perennial ryegrass at 5, 10, 20, and 401 b. per acre and with white clover at 21b. per acre. Under ordinary pasture management cocksfoot sown without rye-

grass does not produce a satisfactory sward owing to slowness of establishment, and even with small amounts of ryegrass it is suppressed where the soil is fertile or well topdressed. The heavier rates of sowing of cocksfoot had little effect on establishment because of the strong competition from ryegrass. More than 51b. per acre in the mixture, certainly not more than 101 b., is not advised. Even these sowings may be difficult to justify except in poor , country or where the soil dries out. On dry soil 151 b. of cocksfoot may not be too heavy. On poor soil where the moisture supply is reasonably adequate the wisest course would be to buy more fertiliser with the . money which might be used on extra cocksfoot seed if a heavy sowing was made, or to take other steps to make conditions more suitable for ryegrass establishment. Timothy _,. ' + „ . R , . Timothy was sown at 2, 4 6, and 81b. P er acre with ryegrass at 151 b. per acre, and timothy at 61b. per acre was sown without perennial ryegrass and with perennial ryegrass at 5, 10, 20, an j 491 b per re. All mixtures inc u d e d 21b. per acre of white clover, Although conditions on all the trials cunuiuuus uu nn uie ? appeared suitable for timothy estabhshment, results were the same as with cocksfoot. The ryegrass overwhelmed the timothy, and a poor-producing pasture was obtained from sowing timothy alone. Reports did not indicate , that timothy was more severely grazed by stock than other species, Often severe grazing is usual and has been put forward frequently as the cause of a low percentage of this grass found in pastures. A seeding of 41b. of timothy per acre appeared to give as good establishment as higher rates,

and the same remarks apply to the sowing of this grass as apply to cocksfoot. Even this seeding is hard to justify. Timothy is more suited to fairly damp situations and for wet c ii ma t es , and differs from cocksfoot in this respect 1 n j Clover u Red clover trials were carried out with perennial . ryegrass and Italian ryegrass. Sowings of red clover at 2, 4, 6, and 81b. per acre were made with 201 b. of perennial ryegrass per acre and sowings of 51b. of red clover per acre with 5, 10, 20, and 401 b. of perennial ryegrass. Six pound per acre of red clover appeared to give as good results as 81b. with the 201 b. of perennial ryegrass. Amounts less than 61b. did not give as good a . coverage with this plant. With Italian ryegrass, sowings heavier than 351 b. per acre suppressed the red clover and prevented its development and 61b. of red clover was required and was definitely superior to sowings of 31b. For temrary pasture, therefore, 25 to 301 b. o Italian ryegrass plus 51b. or 61b. of red clover appear to give the best results. This is in line with recommendations made by Instructors, u»i.. p|» r vvniTe Clover Sowings of 1,3, and 51b. of white clover per acre were made with 201 b. per acre of perennial ryegrass and 21b. of white clover per acre with 15, 25, and 451 b. of perennial ryegrass per acre. In the 2 or 3 years after establishment the lib. seeding has not produced as good a sward as the 21b. or 31b. seeding and the 51b. seeding is not warranted. At least 21b., which is generally recommended, should be sown.

SEEDING RATES FOR PASTURES ON PLOUGHABLE LAND IN AUCKLAND

Subterranean Clover Sowings of I, 1,3, and 61b. per acre of subterranean clover were made with 151 b. per acre of ryegrass and a sowing of 31b. per acre of subterranean clover was made with 21b. of white clover and 151 b. of ryegrass. The 31b. sowing was most satisfactory and the 51b. sowing did not appear warranted. At least 21b. should be sown. The combination of 21b. of white clover and 31b. of subterranean clover was strikingly superior to the sowings of subterranean clover only. In summer and early autumn, when the subterranean clover was dead or there were only small seedlings, the ryegrass obviously suffered because no white clover had been sown. Because of the bulk

of leaf produced in spring, subterranean clover is worth including, particularly for pastures where sheep, especially lambs, are grazed. Conclusions The results of the trials and general information indicate that for dairying the following mixture is suited to country of reasonably good fertility where a good seed-bed is prepared and the seed sown at a suitable time for establishment in autumn.

lb. Perennial ryegrass .. .20 Short-rotation ryegrass .. 10 Cocksfoot .. .... 5 White clover .. .. .. .. 2 Red clover .. 4 41

Where paspalum is required and can be grown, up to 81b. of this grass should be included. On clay soils where red clover establishment may ' not be obtained unless the soil is extremely well treated the sowing of this clover may be reduced to 2 or 31b. Short-rotation ryegrass may be increased or diminished at the expense of the perennial ryegrass according to soil conditions and pasture management to be followed. On pastures for sheep and cattle the following mixture can be advised for general conditions:—

lb. Perennial ryegrass .. .. ..25 Short-rotation ryegrass .. .. 5 Cocksfoot .. .. .. ~ 5 Crested dogstail .. .. .. 3 White clover .. .. .. .. 2 Red clover .. .. .. .. 3 Subterranean clover .. ... 3 46

No attempt has been made to prescribe mixtures for special conditions such as peat soils, tidal flats, limestone country, or alluvial swampy land where other species, including Lotus major, Yorkshire fog, or strawberry clover, may play an important part.

Treatment Density of Perennial Plot Paspalum lb. ryegrass Paspalum lb. Paspalum Browntop Browntop I o 10 1 6 2 4 10 2 6 3 8 10 3 6 4 16 10 6 5 5 0 20 0 4 6 4 20 3 4 7 8 20 5 4 8 16 20 6 4 9 2 40 1 2 10 4 40 1 2 II 8 40 2 2 12 16 40 4 2 13 R 0 6 6

Short-rotation Perennial Total ryegrass ryegrass ryegrass lb. per acre lb. per acre lb. per acre 10 0 10 15 0 15 25 ■ 0 25 35 0 35 45 0 45 . 0 30 30 5 25 30 .10 20 30 20 10 30 25 5 ■ 30