Additionally, sNUE produced estimates of system efficiency that were more stable across weather years and less correlated to other metrics across distinct crop sequences and N fertilizer input levels.
Around typical nitrogen fertilizer input levels for north-western Europe between 100 and 200 kg/ha/yr the marginal economic return for a farmer on fertilizer-N ranges between 1 and 3 euro/kg of N (fertilizer prices between 2000-2006 were 0.6-0.8 0.6-0.8 of N; wheuro/kgces 125 euroftoN and yield response to N ranging betwheat10-35 kg wheat/prices).
At the Swiss site, which tested red and white clovers, a comparison across N-fertilizer input levels revealed a high potential for N-fertilizer replacement: grass clover mixtures containing 40 60% clover and receiving 50 or 150 kg ha−1 year−1 fertilizer-N achieved the same yield as grass monocultures fertilized with 450 kg N ha−1 year−1 (Nyfeler et al., 2009).
The experiment was an incomplete factorial design with two factors (water supply and fertilizer input) with five levels each, and had a total of 13 treatments with three replicates each.
As noted by McGuirk and Mundlak ([1991]) in their study in India using choice of technique framework, HYVs require high levels of fertilizer input and irrigation to realize the yield potential.
The four crop management systems (CM) were designed with a decrease in input level (seeds, N fertilizer, fungicides, growth regulator) from CM1 to CM4.
Nutrient retention capacity is of particular importance for the effectiveness of fertilizer applications and is therefore of special relevance for intermediate and high input level cropping conditions.
However, among management-related environmental factors considered, only fertilizer input was consistently subsidy-type dependent (highest inputs at medium subsidy levels).
Steadily increasing fertilizer input might contribute the most to the rise of cereal aphids.
Increasing fertilizer input has a major influence on the material flow in the agroecosystem15.
Crop diversity, fertilizer input, and wheat yield per unit area were all increasing during this period.
