Farming perspectives.

Combining economical and ecological goals in farm advisory work by means of simple models.

 

Göte Bertilsson, Dr

Greengard AB, Dösjebro, Sweden.  bertilsson@greengard.se .

 

Background.

 

The main goal for a farm manager normally is, and should be, to maximize the economic result of the enterprise. A crucial question is the planning horizon: the next year, two – three years ahead or even longer? Long- term considerations are difficult. Yet they are necessary in a soil based production.

A farm is also an ecological and environmental enterprise. In increasing degree the society poses demands in this respect. However much the farmer would like to comply he has to consider the economic viability of environmental measures. His planning situation has been  further complicated.

 

Calculation tools, “models”, spreadsheets for planning, are being used for different parts of the agricultural production process, for instance rotations, machinery use and animal nutrition. The aim of this work is to combine economy and ecology, to include and quantify longterm considerations as well as environmental consequences and involve the farmer in the process.

 

Farming perspectives.

 

The “models” are Excel spreadsheets which contain data and information as well as tables for calculations. The process is interactive with the farmer as an important actor. He should be in control, only he knows the local data and can judge the situation on his own farm. And without his acceptance the results and the advice are of little value.

 

Components:

Cropping sequence with yields, prices and costs.

Soil carbon (humus) balance, its development and likely longterm effects.

Indicators of diversity, nitrogen leaching, pesticide use, traffic intensity and diesel requirement. Two alternatives are considered: the present situation (alternative 1) and an improved example (alternative 2). Focus is on changes in alternative 2 compared to 1. This reduces the input requirement and facilitates the work greatly.

 

The system is now beginning to come into practical use. The experience so far is that in at least 7-8 cases of 10 it is possible to find solutions giving both better economy, better longterm sustainability and better environmental performance. True win – win situations.

 

A key variable: cropping sequence.

 

The starting point is the rotation or the normal cropping sequence. The results of all available Swedish and some Danish rotation and pre-crop experiments are summarized and are available as background data in the spreadsheet. It is important that these data have been put on a common reference level (in this case a varied cereal cropping sequence). Effort has been put in extracting quantitative data also from more diffuse scientific descriptions. Without figures the knowledge cannot be used effectively in the planning process.

 

In fact this data collecting work was very rewarding. The combined knowledge was found to be quite consistent. It is presented for each individual report so that both the consistency and the existing variation can be shown, discussed and considered..

 

The farmer provides his normal cropping sequence, yields (his true recorded yields) and prices.The practical work situation can be use of a common computer, or, more efficiently, both the farmer and the advisor works “from home” with the same program and with telephone contact.

 

Then improvements are discussed. It can be to replace a barley crop with an oilseed, legume or even green manure crop, it may be introduction of cover crops, reduced tillage etc. This results in an Alternative 2 to consider.

 

The first step is to discuss changes in yields caused by the introduced “improvement”. The word “change” is important. Concentrating on changes makes the process easy.

 

The next step is to adjust the changes in production costs. Standard values are given as background information, but the farmer has the final word. The work and machine situation is considered. Should only direct costs be used or are also capital costs influenced? That depends on the situation.

 

Then this first part is finished. We get the economic difference between the two alternatives. It is very easy to test the sensitivity for variations in yield effects and costs. What could happen if..?

 

Soil carbon.

 

Based on the cropping sequences the soil carbon development is calculated for the two alternatives by means of Carbon Perspectives, Cpersp, which is presented in a separate paper. Typical issues to consider are: leys, green manure, straw removal, cover crops, delayed soil tillage, manure use.

 

The result can be used for longterm considerations of the sustainability of the system. If the soil carbon content is low, an effect on yields is considered. A review of existing data points to yield effects of about 3% per 0.1% carbon, if the content is below 2%.

 

Other parameters.

Indicators of the diversity of the system, the proportion of nondisturbed land during autumn – spring, the use of pesticides and the use of tractor fuel is attained in the process.

 

An example of results.

Starting point: a rotation with barley, winter rape, winter wheat, sugar beets, summer wheat. Yield level 6-8 tons for cereals. If barley is replaced by a ley for green manure,  the profitability increases by SEK 86 per hectare and year (about $10) and all environmental parameters are improved. For the individual barley crop the farmer looses an income of 5800, but when cost  reductions and yield increases on other crops are summarized there is a net profit, although modest. And soil and environment has gained.

 

 

 

References