Comparison of nitrogen use efficiency of manure and inorganic fertilizer based on long term field trials in Hungary

Sustainability cannot be achieved without improving soil conditions. However, it is estimated that between 60 and 70% of EU soils are unhealthy. Thoughtful use of exogenous organic matter can help restore soil functions and thus improve soil health. Animal manures are the most abundant organic matter in agriculture and, in addition to their high nutrient content, they contribute to improving soil health in many ways by increasing soil biological activity. For these reasons, their efficient and environmentally friendly use is of major importance.

The TUdi project will contribute to develop healthy and productive agricultural ecosystems, where the organic fertilizers play an important role in the nutrient supply of the plants. The ongoing development of the nutrient management tool has to consider the different behavior and characteristic of these materials. Our study gives an example of how the long term field trials results can be implemented in this process.

37 trials have been selected from the database of the Hungarian field trials which contain the effects of farmyard manure and mineral fertilizer application on the basis of NPK nutrient equivalence. Among the various treatments, the yields of the absolute control, the farmyard manure treatment and the one with equivalent amounts of NPK in the form of mineral fertilizer were evaluated. The experiments were grouped according to the soil texture.

Annual fertilization was more favourable in all cases than periodic manure application. Differences between yield surpluses declined with an increase of soil clay contents. The efficiency of fertilization in both farmyard manure and fertilizer treatments were higher on sandy soils, which have the poorest natural nutrient supplying capacity.

The correlation between the changes in the organic matter (OM) content of the control plots soils, and differences of the responses to nutrient applied can be described by hyperbolic functions. A similar correlation was established between the AL—(ammonium lactate) soluble K contents and differences of the responses to farmyard manure and fertilizer.

As the values of these two soil parameters increased, the advantage of the nutrients given in the form of fertilizer over farmyard manure declined.

 

Keywords: long term field trial, manure application, fertilization, nitrogen use efficiency, nutrient advisory system