Crops Grown Without Cultivation

Press, Volume CVI, Issue 31089, 18 June 1966, Page 9

Crops Grown Without Cultivation

Crops like wheat, rape and choumoellier, as well as grass species, can be grown satisfactorily without cultivation of the soil before sowing. Mr R. Taylor, a research officer in the South Island team of the research and development department of Imperial Chemical Industries (N.Z.), Ltd., has shown this to be the case in the last year in trials in Canterbury and Southland.

“I would say that the results so far are reasonably encouraging,” said Mr Taylor this week in discussing the progress of the work. “I think that we have demonstrated that crops will grow quite normally without soil cultivation. There are, however, certain problems that have still to be overcome, but we know what those problems are and in the future our efforts will be directed at overcoming them.”

about an inch and a half deep and six inches apart. None of the initial chemical treatments checked the clovers in the old sward for a sufficiently long period and to deal with them a second chemical spraying was given between drilling and emergence—a little more than a week later on December 3.

At the same time a strip was given normal cultivation and sown in 21-inch rows after a very short three weeks fallow. Visually at least the cultivated ground appeared to give better earlier growth than where the seed had been directly introduced into the sprayed sward, but factors in this may have been wider row spacings in the cultivated area and that seedlings may not have been so readily discernible on the sprayed areas, either still being concealed in the slits or by litter on the soil surface. Where no second spraying was given to the chou moellier on areas direct drilled the chou moellier is still very poor, being sparse in plant numbers and with small plants in a strong clover sward base.

In Southland, Mr Taylor has been working with wheat, chou moellier and swedes, and even peas, and in Canterbury with barley, rape, chou moellier, swedes and pasture species.

In all these trials the method used has been to introduce the seed following chemical spraying to kill out or check the existing vegetation. The availability of a group of chemicals called the bipyridyls .these include paraquat marketed as Gramoxone) has made it possible to have another look at this method of seed introduction for the reason that they do not have any residual effect in the soil, such as would effect germination and subsequent establishment. This week two of Mr Taylor’s trial areas were inspected. One is in a 15-acre fairly steeply sloping paddock on the Homebush property at Coalgate. This paddock had been down 34 years before a start was made to work it last year. The trial area is two acres. It was left uncultivated when a start was made to cultivate the rest of the paddock for turnips which were sown early in January. After being fairly hard grazed the trial area was sprayed on November 23 using paraquat with various other similar chemicals in various combinations and different treatments. The very next day the chou moellier was introduced by a Duncan drill fitted with overdrilling skeiths and slightly modified coulter tips. These ' si” he ■'il

Where respraying was done the clovers were checked on part of the area and killed on the remainder. Where there was only a checking of the clovers the addition of IJcwt of sulphate of ammonia lifted the yield from 14 tons to the acre to 21 tons, while where the clovers were killed the increase with the same weight of sulphate of ammonia was from 22 tons to 25 tons to the acre. At the same time the production off the cultivated area was only fractionally better than for the best direct introduced treatment at about 27 tons to the acre. Here no nitrogen was used.

The checking or killing of the clover with the possible release of nitrogen to the seedling plants could well be ’ irtant factr in sue-

cessful direct crop seed Introduction, and at the same time it way well reduce the need for expensive nitrogenous fertiliser applications. From a research point of view Mr Taylor is interested in the possibility of perhaps using a preliminary spray to knock out the clovers and then another to deal witn the grasses, but he recognises that from a practicable point of view one spray is desirable. • Weeds Were more of a problem on . the cultivated ground than on the sprayed areas although some fathen struck along the drill rows on the spray treated plots. To Mr R. G. Deans, of Homebush, it has been remarkable that it has been possible to grow chou moellier so successfully without cultivation—as successfully or nearly as successfully as where the soil was given ordinary cultivation treatments.

A point in favour of the direct introduction method in Mr Deans’s mind is also that the ground would possibly be easier to cultivate after the winter, not having been so susceptible to pugging in its uncultivated state during that period. Before the economics of the direct introduction technique can be closely examined, Mr Taylor believes that a fuller understanding of all of its implications is necessary. Certainly the longer period that a pasture is available for use where it is due to be broken up is another factor in its favour. Ultimately Mr Taylor envisages that it may be possible to develop a whole rotation based on direct introduction, with no or only minimal cultivation.

A small area on the Homebush trial area was also direct drilled with swedes. These were not sprayed a second time to check the clover and the bulbs are fairly small in size. In general Mr Taylor says that trials with swedes so far have been unsuccessful due mainly to fertiliser damage affecting germination and the regrowth of clovers competing with the swede seedlings. Root crops appear to be more susceptible to this sort of competition. This autumn work has begun with the idea of following up and possibly extending present methods of using chemicals for improving pastures without resorting to cultivation.

On Mr H. C. Deans’s adjacent Tara property pasture and winter feed species have been introduced into swards with the idea of looking at pasture improvement or replacement and the possibility of growing winter feed by this method. Here on a browntop sward Gramoxone at a half-pint, one pint, two pints and four pints to the acre has been used with one area being left untreated altogether. These treatments were carried out on March 31, and on April 6, with the same drill, Ariki ryegrass, perennial, short rotation and also some Winter Grey oats were introduced separately. All have established well although the sowing was rather on the late side and Mr Taylor says that better results might have attended January or February sowing. The same treatments have been applied in a rather better pasture and on possibly more fertile soil on a higher part of the same property, again with promising results. With the lighter chemical dressings clover has recovered faster than with the heavier ones. Mr Deans is Interested in the possibility of introducing winter feed in this way. For

he says that on their country there can be up to a 40 per cent loss of feed With turnip feeding in the winter under wet, muddy conditions. Mr Taylor said that he was planning shortly ,to drill wheat directly Into a sprayed two-acre area at Darffeld. So far experiments with wheat have been with spring sowing in Southland in the Winton district.

There on the property of Mr R. J. A. Miller a seven-year-old pasture was hard grazed early in October last year, sprayed and then about a week later Hilgendorf wheat was drilled directly into the sprayed pasture. Thistles and clovers in the wheat were subsequently controlled by spraying a mixture of M.C.P.A. and dicamba in December.

Yields ranged from 64 to 78 bushels to the acre with the upper yield being associated with the use of 2cwt of sulphate of ammonia at the time of sowing as well as 2cwt of superphosphate. Wheat cultivated in the normal manner alongside the direct drilled wheat yielded 66 bushels to the acre. There were no differences in the baking quality between samples of wheat from different fertiliser treatments or between direct-drilled wheat and wheat grown after full cultivation—the baking score was high for all samples.

The results of two trials in the Halswell and Lagmhor districts where barley was sown by the direct introduction technique have been inconclusive. A major problem appears to be to prevent bird damage at the time of drilling. Yield has been shown to be increased by the addition of nitrogenous fertiliser and also by the application of a hormone weedkiller at the tillering stage to check clover growth. At Rakaia the direct introduction of rape was the subject of a trial on the property

of Mr D. R. Langley. Here the pasture was sprayed on October 30 and Broad Leaf Essex rape was sown with the Duncan drill, as already mentioned, on November 3. For yield the area was sampled on January 11. Where the land was given the traditional cultivation treatments the yield was 5.2 tons of fresh feed to the acre. Without any nitrogen treatment the yields on the direct drilled areas ranged from 1.3 tons to 3.9 tons to the acre, but where lewt of sulphate of ammonia was broadcast one day after drilling yields increased to between 3.2 tons to 6 tons to the acre. Fathen was the predominant weed in the cultivated area and some fathen also germinated in the drill rows on the direct introduced areas, where the crop grew mainly in association with clovers, which recovered from the chemical treatments.