Section 1: Reflecting on your farming system

Farming systems are complicated because they are not static. Everything changes: the weather, the competitors for resources and the crop itself.

To make reflection easier, and to put today’s observed problems into a context, think of your farming system as interlinked components of inputs and outputs.

Management attempts to put as much as possible of the farm’s resources into harvested high-quality grain. All along the path from before sowing to harvested grain there are competitors for those resources. The aim is to minimise the effects of those competitors and give the crop its best chance of expressing its potential.

In thinking about the system and about whether it can be improved, go through the following general steps and questions.

• List your main inputs and outputs. Think not only in terms of this year’s economics, but also in terms of next year and the impact of current decisions on the economic sustainability of the farm 10 years in the future. List the rotations used in recent years.

• Question whether you can manipulate environmental inputs. Are the natural inputs of sunlight (solar radiation), rainfall, nutrients and soil air (aeration) being used optimally within the system or wasted. If their effects are negative such as is the case with frost or high temperature, consider how those effects could be minimised. For example, is the date you plant and the variety you use best for your area, considering the environmental constraints?

• Could harvested grain be a higher proportion of outputs? Could more of the inputs supporting diseases, weeds and pests be reallocated to grain; could the crop stubble and straw be used to increase production of the next crop; could applied water be used more efficiently in producing grain?

• Is the management system environmentally sustainable? Or are natural soil and water resources being gradually downgraded or over utilised? Is the irrigation methodology progressively increasing soil salinity; are diseases building up, should a changed crop rotation be considered to control pests and diseases, should there be a change from flat-land flood irrigation to a permanent raised bed system to reduce erosion, siltation and waterlogging?

• Are the yield targets too high for the location? Would a lower yield target lead to a more efficient use of resources?

What is your target yield?

To have an idea of the potential yield of your crop find out what is the highest yield achieved by farmers in your community. Aim for that target to begin with. Be aware however that as target yield rises diseases and pests may be harder and more costly to manage. This is because a high yield requires a dense crop and pests and diseases can spread rapidly in such conditions once an infection is present. You should assess whether the likely additional cost of materials and labour and your time would be recouped in the additional yield. Also you should consider whether additional chemical inputs required might reduce the long-term sustainability of the farm. If you multicrop, the other crops in your system may also influence your target. Time of harvest for these crops may delay the planting of wheat in the same fields beyond the optimum time for your area.

The list below summarises the main requirements for a target yield of about 5t/ha that is feasible on irrigated land in many regions. It assumes that the crop is planted in 7” (18 cm) rows at the optimum time. If you use a different spacing you need to change the values listed. It shows what characteristics the crop should have as it progresses through its Zadoks stages (see drawings starting on page 9 for details of the Z numbers). Adjust the listed values up or down to match your target. The numbers in the table were provided by M Stapper.

Characteristics of a 5t/ha crop as it grows

These characteristics assume that the crop is planted in 7” (18 cm) rows and that management is as described in the notes below the table. The total nitrogen required (both residual and fertilizer) for this crop growth is 120-150 kg/ha, applied at tillering stage.

Notes:

Sowing date should aim for the optimum flowering date for the region.
Lodging should not occur before Z7.8 as this considerably reduces yield.
Potential kernel weight is achieved by avoiding water stress up to early dough stage Z8.0. No irrigation is required thereafter.
Yield estimate assumes a 10% loss (harvest and area losses) and that the grain has a moisture content of 10%.