Reduced till and the bottom line

A 2016 study looked to quantify the economic and environmental implications of reduced intensity tillage practices when crop mixes are optimised for profit (gross margin).

Six tillage systems were compared:

  • Conventional (CT)
  • Rotational ploughing (RP)
  • Deep reduced tillage (DRT)
  • Shallow reduced tillage with medium disc harrow (SRT1)
  • Shallow reduced tillage with spring-tine harrow (SRT2)
  • Zero tillage (ZT)

By reducing the intensity of tillage it was found that farmers could increase gross margins and net energy whilst reducing their green house gas (GHG) emissions.

RP DRT SRT1 SRT2 ZT
Gross margin (£ farm−1) +14% +23% +23% +24% +35%
Net energy (GJ farm−1) +2% +8% +8% +8% +9%
GHG emissions (kg CO2-eq farm−1) -5% -9% -9% -11% -11%

Table 1: Gross margins, net energy and GHG emissions for each tillage system in comparison to conventional tillage

The study found:

  • Gross margins were higher for reduced till systems.
  • All reduced till systems had similar gross margins.
  • Higher net margins for reduced till systems reflected the reduced labour, machinery and fuel costs.
  • Time and labour requirements of conventional tillage were higher as a result of the slow work rate of the power harrow. The time and labour requirement often exceeds the farms resources meaning work is contracted out increasing costs.
  • To spread out the workload and limit contractor costs in the conventional tillage system, a less valuable crop mix was untilised. Reduced till systems require less cultivation, as more resources are available a more valuable crop mix could be grown.
  • Although reduced tillage frees up resources, reduced tillage restricts the use of root crops. Therefore flexibility of crop choice is reduced.
  • Two sets of machinery are required for rotational tillage systems so machinery costs are similar to that of conventional tillage systems. However, machinery use is reduced.
  • SRT1 requires a smaller tractor than DRT, but as the work rate is lower gross margins remain similar.
  • Gross margins remained higher in reduced till systems compared to conventional systems when additional herbicides were required for black grass control.
RP DRT SRT1 SRT2 ZT
GM (£ ha−1) +14% +23% +24% +23% +25%
Fuel use (L farm−1) -23% -47% -47% -54% -58%
Contractors’ fees (£ farm−1) -74% -78% -78% -78% -78%
Machinery costs (£ farm−1) -3% -7% -24% -27% -30%
Machinery costs (£ ha−1) -3% -6% -24% -27% -30%
Fuel costs (£ farm−1) -23% -47% -47% -54% -58%
Fuel costs (£ ha−1) -22% -47% -47% -53% -58%
Labour costs (£ farm−1) -14% -39% -40% -31% -45%
Labour costs (£ ha−1) -14% -39% -41% -32% -46%
Net margins (£ farm−1) +23% +39% +51% +56% +59%
Net margins (£ ha−1) +22% +39% +51% +56% +59%

Table 2: Fuel, labour, machinery, and contractor costs and the resultant net margins for each tillage system in comparison to conventional tillage when crop mix is optimised for gross margins.

Uptake

Although yields are reduced, a zero till system can absorb reduction in yield of 14.2% before the gross margin falls below that of a conventional till system. A rotational till system can sustain a yield reduction of 8.1%. This ultimately means that more land will be required to produce yields required to maintain total food production. The benefits of zero till over shallow reduced till are minimal.

  • Cost savings are the main consideration for uptake in Northern Europe.
  • 30-40% of arable land in England is under reduced till cultivation, most in the from of mixed tillage systems.
  • Rotational ploughing is common as some benefits are achieved whilst minimising risk.

Barriers to uptake

  • Change in machinery requirements (capital and learning costs)
  • Benefits are uncertain
  • Farm size – smaller farms are less likely to be able to cover costs associated with changing system.
  • Crop rotation
  • Climate
  • Soil type
  • Difficulties with increased weed burden
  • Yield penalties

Reference

Townsend, T.J., Ramsden, S.J. and Wilson, P., 2016. Analysing reduced tillage practices within a bio-economic modelling framework. Agricultural systems146, pp.91-102.