Conservation tillage gets a thorough working over

Press, 11 May 1984, Page 16

Conservation tillage gets a thorough working over

By

HUGH STRINGLEMAN

Few topics in arable farming circles generate as much heat as conservation tillage, which is now taken to mean practically any crop establishment method short of a thorough conventional working up of the soil.

One definition is that conservation tillage is a system of plant establishment where vegetation control and seedbed preparation by cultivation is minimised or replaced by the use of herbicides. At the third Monsanto conservation tillage seminar in Christchurch last week, Mr Bob Engelbrecht, a farm consultant from Ashburton, prefaced his address with a joke at his own expense. His colleague, Mr Barry Croucher, had “ploughed a path to the door and was waiting with a warmed-up car” for the Engelbrecht getaway, he said. A short way into his address it was evident why Mr Engelbrecht felt like “a pork pie at a Jewish wedding.” He was not prepared to wholeheartedly endorse conservation tillage. Many of his top farming clients had tried the system and had not continued with it. He had tried it for himself, taking all the advice given by merchants’ representatives and using contractors who were themselves keen on C.T.

Although he was taking very small paddocks out of pasture on his own 12ha farmlet, which he acknowledged was a stiff trial for C.T., crop establishment was poor and slow. “The claimed benefits of C.T. are not yet achievable by the average farmer,” he said, “who is not interested in what benefits he might gain in three years time but how he will pay his bank manager this year. “Practical problems always arise and Monsanto might have to put more people on the ground to be there when the problems come up,” he said when concluding his address. “Block the door,” said conference session chairman Dr Warwick Scott from Lincoln College, and Bob Engelbrecht had to stay and face the music. Just as he must have expected comebacks from an audience liberally sprinkled with Monsanto

employees and conservation tillage advocates, he must have also been pleasantly surprised by the lack of criticism in the questions which followed.

Monsanto representatives such as the New Zealand manager, Mr Allan Scherp, and the conference “moderator,” Mr Gerald Atkinson, had stressed at the beginning of the seminar that it was to be a fullyfledged extension exercise.

“Warts and all” was certainly implied.

About a decade after the widespread introduction of glyphosate in New Zealand, sold to farmers by Monsanto as Roundup, many lessons had been learned and could be passed on, they said.

Clearly the company’s extension task is a complex one and one that it tackles with enthusiasm and forthrightness. Including Bob Engelbrecht on the programme proves that.

Monsanto has an effective chemical which does a sterling job in most of the situations it is used. If it is used correctly, at the recommended application rates, it probably does all of the things farmers ask of it.

But in order to sell more of the chemical, Monsanto has to promote a revolution in crop establishment. For an analogous situation it might be imagined that to sell more anthelmintic, another agricultural chemical company has to promote a new breed of sheep. To influence a change in crop cultivation practices which have been used by farmers for thousands of years is a tall order, no matter how many factors are in favour of a change. And as in any revolution, there are opposing forces which sometimes come together with some heat and, in the case of the Monsanto seminars, plenty of welcome light. Dr Gerald Frengley, in the Farm Management Department of Lincoln College, said that annual machinery costs on a farm which derived more than 20 per cent of its income from crops could be estimated at about $450 per hectare of land cultivated. If it was assumed that two-thirds of these costs were connected with cultivation, not trucks or headers, and the figures from the 1981-82 season were adjusted for inflation to the 1983-84 season, the machinery cost was around $350 per hectare cultivated. Nationally this meant an

expenditure on arable farms (those with 20 per cent or more of crop) of $B3 million. He conceded that the base year from which his figures were calculated might have been a year of high machinery replacement. But he maintained that a shift to C.T. must be seen as nationally desirable if it substantially reduced this $B3 million input C.T. had not penetrated as much as many had expected and Dr Frengley suggested that this was due to taxation concessions which favoured agricultural machinery replacement. Such replacement for many farmers was “an opportunity thing in good years” and farmers then mentally wrote off the cost of the expensive machinery in that year.

But allowing for the taxation provisions probably reduced machinery cost per hectare on cultivated land to around $270, he said. A cost per hectare of $B3 for three litres of glyphosate gave a break-even cost for machinery at 6.3 hours per hectare to crop establishment and glyphosate at two litres per hectare ($55) gave a break-even point of 4.6 hours per hectare. Many farmers operated in excess of these machinery times per hectare for crop establishment and were therefore in areas where a shift to C.T. would be beneficial.

Also a saving in fuel nationwide of 22 million .litres per year could be achieved if half of the arable farmers switched to C.T.

He concluded that an annual saving of $25,000 per year per farm could be expected without a reduction in yields. The true long-term saving to New Zealand of a switch to C.T. by all arable farmers who would benefit could be more than $lOO million a year. Continuing in this positive vein, a Monsanto rep Mr Murray Willocks, of Christchurch, outlined his five rules for successful crops with minimum tillage. © Plan well in advance with soil tests and appropriate utilisation of any sprayed-out pasture which is there to be used. • Choose the correct rate of herbicide application and apply it correctly with appropriate dilution.

© Use an insecticide if necessary.

@ Use direct drilling equipment designed for the job (at least five direct drills are on the market). ® Use adequate fertiliser, particularly nitrogen which

might be locked up more with direct drilling. Planning was particularly important, Mr Willocks said. For instance a pH correction might require lime up to six months before crop establishment with C.T. If one operation in the sequence was not done correctly then it would impact on the crop, whereas in conventional cultivation an operation could often be repeated. “Don’t short cut on a short cut,” he pleaded. Another partner in the Ashburton consultancy, Engelbrecht, Royds and Tavendale, Mr Terry Wall, said C.T. should be considered in the following farming situations: ® Where an increase in arable area or pastoral renovation is considered and plant and machinery are aged. ® Where on-farm labour is over or under utilised and C.T. may more satisfactorily balance the available labour. ® Where capital required or debt servicing is going to prove a real hurdle to upgrading machinery. © Where cultivation costs are traditionally expensive due to difficult soils. @ On mixed farms where time is critical. “Probably one of the biggest stumbling blocks to C.T. adoption by fanners has been frequent winterfeed failures after spraying and direct drilling and the three main reasons are failure in chemical control of herbage, inadequate moisture or poor seed placement. He felt the first two problems could be overcome with a chemical fallow (an early spray with Paraquat to get hardy annuals growing vigorously before the Roundup). But high rates of chemical were no substitute for an effective C.T. technique. Nor would Mr Wall encourage any adviser to encourage a farmer to direct drill unless the adviser was personally convinced that it would be worth while. Two farmers followed with positive recommendations for C.T. Mr Bruce Leitze, of Kelso, West Otago, said that he had changed three years ago to a C.T. system on his 95 ha mixed farm because he was bored by tractor work, felt he could save

fuel, believed C.T. had developed to the stage of reliable yields consistently under continuous cropping with no soil structure changes, would save labour inputs and eventually lead to considerable savings. He had variable yields with highs of 7.5 tonnes per hectare for wheat and barley and lows of 4 tonnes per ha with barley. Successful crops had good paddock drainage, suitable subsoil, good weed .control and burn-off and even drying of paddock. Unsuccessful crops had been those when these factors were reversed.

Mr Bruce Henderson, of Methven, said that he calculated that he had saved more than $320,000 in labour costs during the 10 years that he had been direct drilling. He thought this was a saving of 80 per cent of the labour input to the amount of crop that he grew during that period had he conventionally cultivated.

He had around 600 ha of irrigated land of which twothirds was under crop and the whole farm was worked with three and a half labour units. Seven would be needed for conventional cultivation, he maintained. Moreover, his sons and he did their own spraying and fertiliser spreading. For the 400 ha of crops planted each year the conventional tractor time would be 1300 hours, he calculated, but C.T. had reduced this input to 180 hours.

In his calculations the saving in diesel costs was balanced by the cost of Roundup but there had also been a saving in lime applications.

Altogether he maintained that he was better off by something approaching $40,000 per year over the 10 years.

Dr Garth Janson, from the M.A.F.’s Winchmore Irrigation Research Station, reviewed his comparative research into direct drilling and conventional cultivation over the past six years under continuous cropping with cereals, white clover and legumes.

No clear and consistent differences between the two methods had been observed in soil physical parameters but soil chemical measurements had showed that organic carbon and total ni-

trogen levels were falling slowly under conventional cultivation but being maintained under direct drilling. Phosphate levels in the topsoils were substantially higher on direct drilled plots after only three years because soils were not being turned under.

Earthworm populations had risen dramatically to three or four times larger under direct drilled plots after five years. Grass grub numbers were also much higher, but they didn’t seem to have too much detrimental effect.

His findings indicated that on light, well-aerated soils direct drilled crops had no greater requirement for nitrogen fertiliser than conventionally established crops. On heavy soils spring-sown crops, and to a lesser extent winter-sown crops, will have a greater requirement for nitrogen fertiliser for the first year or two after direct drilling is adopted. On lighter soils crop yields remained on a par right from the start of direct drilling but on heavy soils an initial drop of up to one tonne per hectare was recorded. With experience this yield imbalance was corrected, and over a longer period very little difference was observed between the two systems in total crop yields. Significant savings in establishment costs are being recorded on light and heavy soils under direct drilling but differences in final gross margins are not great. The big saving is in labour, said Dr Janson, of up to 70 or 80 per cent of time spent in crop establishment. The controversial Mr Engelbrecht said that he

had observed self-deception among C.T. advocates and he suggested that many might be happy with reduced yields, but this would not be the case with his top clients.

Some of these top farmers had tried C.T. but then not continued with the practice. They weren’t negative and would have adopted it if the opportunities to make genuine savings had been apparent. “My top clients rarely have crop failures so the change in technique (to C.T.) must be near foolproof to be worth while.

“But I would really like one of my top farmers to persist with C.T. because he would be more likely to make a go of it than the average farmers who seem to take it up and have failures.”

He was nonplussed by the number of claimed foolproof C.T. recommendations for exactly the same location and task. He concluded that he had no dispute with Roundup, which certainly did its job. The new drills for C.T. required many more improvements and he hadn’t seen any real reductions in labour input with direct drilling.

Although the promotional literature for C.T. said it was straightforward, this was not the case and the technique must work with average farmers in average conditions. He offered Monsanto freerun of his farmlet, where C.T. had not been successful, to see if they could make it work.

“If you can convince me then I am pretty sure that you will convince some of my top farmer clients,,” he said.