The cost of reducing nutrient loss from agriculture Dr Bob Crabtree CJC Consulting Ben Wightman Symonds & Sampson

WAgriCo Project in Dorset Survey of a random sample of 19 farms participating in WAgriCo. Cost of providing supportive measures to farmers (catchment adviser)

Farm survey 19 farms across the three catchments, average size 241 ha. Costs estimated for introducing 10 measures to reduce nutrient loss.

Using recommended fertiliser levels Cost per ha (£)   WAgriCo paid £5 per ha (plus free advice)

Preparing and applying a manure management plan Cost quite variable. Average £228, range £0-£1,050. Many prepared as part of an assurance/advisory package and therefore difficult to cost. Highest costs on dairy farms. Usually a saving in fertiliser costs but spreading costs often increased. In most cases no effect on yields. Benefits generally exceeded costs - average net benefit: £9.3 per ha

Cover crops for spring sown crops (maintain until Feb 15th) Only 13 farms had spring crops Cost of establishing and managing: £68.8 per ha (range £20-150) Variety of different approaches to establishment Costs lower when own labour and machinery used. Higher costs when contractors used or problems with burying trash or additional sprays required. Valuable feed on some farms- trash problems on others WAgriCo paid £60 per ha

Fertiliser spreader calibration Cost around £180 per spreader Most farmers had their spreaders calibrated as a matter of course or because a crop assurance scheme required it. Benefits difficult to estimate because baseline (effects of non-calibration) not known. Benefits were large, averaging £15.4 per ha and easily covered costs The net benefit averaged out at £14.2 per ha.

      Moving from autumn to spring application for slurries and poultry manure Only relevant on 4 farms. Others did not produce slurry/manure or spread only in the spring. No additional cost on the 4 farms. Other farms (not sampled) could incur large costs if additional manure storage was needed.

Nitrogen efficiency calculation This is the calculated nitrogen balance for the farm WAgriCo is undertaking the balances and paying an incentive to improve N efficiency – no results yet. Commercial cost expected to be £450 (consultant) plus data preparation by farmer (c. £600 in total)

Convert land in arable or intensive grass to extensive grass (20% of total area) Expensive measure because of lost income especially on dairy farms Extensive grass had some grazing value on livestock farms but incurred costs (topping) on arable farms.

Adopt minimum tillage for all crops except roots and grass reseeds Many farmers already use min tillage. Conversion costs (purchase or contractor) depend on scale. Some land unsuitable. For farmers not using min tillage the additional cost (of using a contractor) was £33 per ha. With some costs saving (£17 per ha) the net cost was £16 per ha.

Cultivate land in spring (after Christmas) rather than autumn (spring crops) Only relevant on 2 farms – others already cultivated in spring or had no spring crops. Additional cost (spraying and some loss of yield) £115 per ha. Not a useful measure in these catchments because little scope to apply it.

Use fertiliser rate 10% below the recommended rate (arable land only) Farmers very reluctant to reduce fertiliser levels with current cereal prices. Significant loss of income expected on most farms

Cost summary Cannot compare effectiveness on these figures alone

Cost of a supportive approach Catchment adviser for 2000 farms

Summary Low cost options (no net cost on most farms) Recommended fertiliser levels (incl. soil sampling) Manure management planning Fertiliser spreader calibration Supportive approach (catchment adviser) High cost (but may have bigger impact on N losses) Reducing fertiliser inputs and conversion to extensive grass