Summary
This report, which is part of NRLO project HELI 2015, contains an overview of the trend in the environmental burden of agriculture and horticulture as seen from different environmental perspectives. Agriculture and horticulture are found to have a relatively large environmental impact in relation to their economic significance. This applies in particular to acidification, the use of manure and the spread of certain chemicals and also, to a somewhat lesser degree, to climate change.
Some aspects of the environmental burden of the agricultural sector have been declining over the last few years. Regulations, levies, grants, information and increasing environmental awareness on the part of farmers and their organizations have contributed to this.
The total consumption of crop protection products by agriculture and horticulture dropped from 21.3 million kilograms of active material in the mid-eighties to 12.6 million kilograms in 1995, in other words by about 40%. The biggest drop - 77% - was in soil disinfectants, as a result of strict regulation of soil disinfection in potato growing. There was little or no decrease in the other categories of crop protection products (herbicides, fungicides and insecticides). As far as most categories of crop protection products are concerned, if present trends continue it looks as though the objectives set for 2000 will not be met. Thanks to the substantial drop in the consumption of soil disinfectants, however, the intended halving of total consumption compared with 1984-1988 will be achieved.
The average consumption of crop protection products in the Netherlands is almost 6.5 kg per hectare. This is nearly four times the average in the EU. If we take differences in the product portfolio and the production per hectare into account, the picture looks significantly better. For example, the growing of tomatoes and roses in countries along the Mediterranean coast results in the consumption of considerably more chemicals per unit product than in the Netherlands. There are big differences in the consumption of crop protection products between one crop and another, and associated with this there are also big differences to be found between regions. There is relatively high consumption in North Holland and the Noordoostpolder (bulbs), in the peat areas of Groningen and Drenthe (starch potatoes), in North Brabant (green maize) and in Central Limburg (green maize and mushrooms).
Agriculture and horticulture account for about 13% of the total Dutch contribution to the greenhouse effect. Their share of CO2 emissions is approximately 6%, but their share of the other two greenhouse gases (N2O and CH4) is substantially higher at 30% and 45% respectively. These gases come from cattle and manure. The emissions of CO2 and N2O increased continually until 1994 and stabilized in 1995. This was also the case for the sector's contribution to acidification, which increased by 12.5% between 1985 and 1994, despite the reduction in CH4 emissions. This last point is primarily the result of milk quotas.
Approximately 80% of the energy consumption in the agricultural sector, and therefore of the CO2 emissions, is in growing under glass. In this sector the quantity of energy per unit of product - the energy efficiency - dropped by 40% between 1980 and 1995. In recent years, however, this downward trend has been rather gradual and there is a question as to whether the objective set - 50% in 2000 - will be achieved. Despite the improvement in the energy efficiency, the overall energy consumption in growing under glass climbed continually from the beginning of the eighties until 1993 as a result of strong growth in production. It is only in the last couple of years that the energy consumption has stabilized.
Less than half the minerals that are brought to a farm or market garden are utilized by the products. The remainder, the mineral residue, remains behind somewhere in the environment. In the second half of the nineteen-eighties soil emissions of both nitrogen and phosphate dropped by approximately 20%. This was due, among other things, to a reduction in the number of dairy cattle, a drop in the phosphate content of the feed, more critical use of minerals in general and, in particular, a decrease in the consumption of chemical fertilizers. Since 1990, however, mineral emissions to the soil have not decreased much at all. The mineral residues are the greatest in sandy areas. This is closely linked to the spread of (intensive) animal husbandry.
Information from the Farm Information Network of LEI-DLO shows that over the last few years the phosphate residue on arable farms has been 55 kg per hectare and some 70 kg on dairy farms. In the context of the manure policy it has been laid down that the maximum allowed loss in 1998 will be 40 kg per hectare. In the meantime it has been decided not to include phosphate from chemical fertilizers until 2000. As a result of this the standard laid down for 1998 is probably achievable by a substantial proportion of soil-related farms. It will probably be more difficult to reach the standard of 20 kg (including phosphate from chemical fertilizers) that will ultimately apply - in 2010 - although it has been found in practice that the residues can be lowered significantly through satisfactory minerals management. A similar picture emerges for nitrate. In recent years the average nitrate residue has been approximately 170 kg per hectare on arable farms and 400 kg on dairy farms. The standards for 1998 have been set at 175 kg and 300 kg respectively, and those for 2010 at 100 kg and 180 kg respectively. A great deal will have to be done, therefore, to reach these standards, particularly in dairy farming.
Ammonia emissions from livestock farming decreased between 1985 and 1995 from 240 to 144 million kilograms, thanks mainly to low-emission manure spreading. Emissions from buildings housing animals, during grazing and from manure storage decreased much less. If present trends continue, the target for 2000 - a maximum ammonia emission of 112 million kilograms - will probably be met. The 2005 objective - a maximum of 70 million kilograms - will be more difficult.
The dresiccation problem manifests itself primarily in the gradual drop in the groundwater level, with all the associated consequences for the natural environment. It is estimated that approximately 60% of the loss of water is caused by the agricultural sector. The accelerated removal of rainwater, in particular, exacerbates the situation. Recently a policy has been introduced to suppress the removal of groundwater and to remove water, including rainwater, in a much more sophisticated fashion in the context of what are described as anti-desiccation projects. The aim is to reduce the drought-affected areas in nature reserves, which amounted to some 600,000 hectares in 1995, by a quarter in 2000 and by 40% in 2010. The first target will probably not be met. The consequence of this policy may be that the agricultural sector, particularly in the vicinity of nature reserves, will encounter a situation that is not ideal in terms of agriculture.
In 1995 the overall contribution of agriculture to the waste mountain (excluding manure) was more than 1.6 million tonnes. That was almost 70% more than ten years earlier and represents approximately 3% of the total amount of waste produced. About three-quarters of agricultural waste is currently being reused.
It can be concluded that some aspects of the environmental impact of agriculture and horticulture are decreasing, but that there is still no real improvement in relation to others. Over the last few years policy has been laid down for virtually all environmental themes in the sector. In the years ahead the sector will have to resign itself to making more substantial efforts in order to further reduce the environmental impact.