Ground water recharge through optimized intensive dairy farms

To meet the increasing demand for water for human consumption, surface water is increasingly used, generally at high purification costs, as ground water availability is limited. Sandy areas can "produce" high-quality ground water based on infiltration and leaching of the precipitation surplus. In the Netherlands, as in many other countries, these areas are used by dairy farms. Because of intensification in the recent past, ground water recharge has declined as a result of increased water consumption by crops and its quality is deteriorating as a result of nutrient leaching. Possibilities were examined to improve management at farm level in such a way that the desired upper ground water quality could be realized and extractable ground water quantity for human consumption increased without reducing milk production intensity (11 900 kg ha(-1)). A prototype farm system was established on an experimental farm. Nitrate concentration in the upper ground water decreased from 200 to 50 mg L-1 (associated with reduced N surpluses) and ground water recharge could be increased by 550 m(3) per ha (through reduced crop water consumption). Additional experimental farming system costs were below the costs for purifying 550 m3 surface water. Therefore, it is concluded that integrating ground water management in dairy farming is technically and economically feasible and therefore attractive for farmers, water companies, and consumers.