Frans Aarts Wageningen University and Research Centre (W-UR) Plant Research International Plantekongres 2005, Denmark Nutrient balances: experiences from The Netherlands

Agricultural facts Netherlands agricultural land: 1.9 million ha animal production: 8 billion euro 24,000 dairy farms (grass, maize) 6,000 pigs/chicken farms (no land) Denmark agricultural land: 2.7 million ha animal production: 5 billion euro

Agricultural facts Netherlands agricultural land: 1.9 million ha animal production: 8 billion euro 24,000 dairy farms (grass, maize) 6,000 pigs/chicken farms (no land) Denmark agricultural land: 2.7 million ha animal production: 5 billion euro Livestock density high very high

Manure-N (1997) Netherlands: kg N/ha on average kg N/ha on dairy farms Denmark: - 90 kg N/ha on average

Effect of livestock density on N balance (Denmark)

Effect of livestock density on N balance (EU, le Gall) 7500 kg milk= 170 kg N-manure

Effect of livestock density on N balance (le Gall) Dutch average

Effect of livestock density on N balance N surplus/ha (= input – output) manure-N/ha

Nitrates directive N surplus manure-N/ha170 kg EU nitrates directive 190 kg

Nitrates directive N surplus manure-N/ha170 kg EU nitrates directive Dutch dairy farms 288 kg 190 kg 355 kg

Effect of livestock density on N surplus N surplus manure-N/ha Individual farms

Effect of livestock density on N surplus N surplus manure-N/ha Individual farms On farm level: livestock density is a weak indicator for N surplus

N-surplus as indicator for environmental effects Quality water N surplus/ha excellent bad

N-surplus as indicator for environmental effects Quality water N surplus/ha peat, grassland average dry sand, arable bad excellent

N-surplus as indicator for environmental effects N surplus/ha peat, grassland average light sand, arable desired acceptable Quality water

N-surplus as indicator for environmental effects N surplus/ha peat, grassland average light sand, arable desired acceptable At farm level N-surplus can be a good indicator for environmental performance Quality water

Surplus N related to nitrate leaching (light sandy soils) Surplus farm (kg N/ha) (mg/l)

Surplus N (1998, kg/ha) Acceptable: 250 ? peat 130 light sand

Surplus N (1998, kg/ha) Acceptable: 250 ? peat 130 light sand Strong reduction of surpluses is needed

How to reduce surpluses? limit to livestock density: animal accounting or Limit to surpluses: mineral accounting

Limit to livestock density N surplus manure-N/ha170 kg Reducing livestock density 190 kg 288 kg

Limit to livestock density N surplus manure-N/ha170 kg 190 kg

Limit to livestock density N surplus manure-N/ha170 kg 190 kg Not all farms below acceptable level

Limit to the surplus of N N surplus manure-N/ha170 kg Improving management 288 kg 190 kg

Limit to the surplus of N N surplus manure-N/ha170 kg 288 kg 190 kg

Limit to the surplus of N N surplus manure-N/ha170 kg 288 kg All farms below acceptable level 190 kg

Mineral accounting, with limited surpluses Advantages: - environmental quality is better guaranteed - more attractive if land is expensive and animal density is high Disadvantages: - High cost to control - Acceptance of EU?

How to reduce surpluses? Improve N-turnover in farm components: less inputs needed herd manure crop soil feed Milk/meat fertilizer 80% 53% 18% 71%

? De Marke De Marke An experimental farm on light sandy soil, with an average intensity of milk production and very tight environmental standards

How to reduce surpluses? herd manure crop soil feed Milk/meat fertilizer 80% 53% 18% 71% 23% 92% 70% 93% Improved N-turnover De Marke

Results Mineral fertiliser-N : 70 kg/ha reduction of 70 % Purchased feed: 2,000 kg dm/ha Reduction of 60 % Surplus N: 150 kg/ha

Results 2004 Mineral fertiliser-N : 0 kg/ha reduction of 100 % Purchased feed: 2,000 kg dm/ha Reduction of 60 % Surplus N: 100 kg/ha

How to convince farmers? Father G. van den Elsen (founder of Rabo-bank, Campina etc.): “It is impossible to convince farmers only with books and journals. The truth should be pumped into their heads by clear, visible examples”. (Sociologie der Boeren, 1918)

Cows & Opportunities Cows & Opportunities commercial intensive dairy farms, demonstrating possibilities to realise low surpluses

Characteristics of pilot farms

Environmental performance pilot farms

IncomeN surplus Measures to reduce surplus Economics

IncomeN surplus measures Pilot farms Economics

IncomeN surplus measures Economics 2,500 euro Pilot farms

Dutch Mineral Accounting System (1998 – 2006) Input concentrates livestock roughage manure artificial fertilizer Output milk, livestock roughage manure Farm gate surplus Farm gate balance

Dutch Mineral Accounting System (1998 – 2006) Input concentrates livestock roughage manure artificial fertilizer Output milk, livestock roughage manure Farm gate surplus Farm gate balance About 70 kg N below real surplus (including deposition, clover etc.)

Permitted farm gate surpluses (kg N/ha) Grassland* Arable land* * On light sandy soils 40 kg less

Real N-surplus of very specialized dairy farms (kg/ha) clay peat sand average Average annual decrease: 38 kg = 11% (-150)

Farmgate N-surplus of all dairy farms MINAS Save area

P 2 O 5 -surplus of very specialized dairy farms (kg/ha) clay5233 peat6240 sand6723 average6029 Average annual decrease: 8 kg = 13% (-31)

The future We love mineral accounting, but European Court of Justice does not 

The future We love mineral accounting, but European Court of Justice does not  We will introduce application standards for fertilizers in 2006

The future We love mineral accounting, but European Court of Justice does not  We will introduce application standards for fertilizers in 2006 We expect that costs will increase for farmers , but costs for government will be lower

The future We love mineral accounting, but European Court of Justice does not  We will introduce application standards for fertilizers in 2006 We expect that costs will increase for farmers , but costs for government will be lower We hope that in the future a mineral accounting system can be reintroduced, because nutrient surplus is the better indicator for environmental quality

Thanks!