A series of trials carried out in collaboration with several universities around the world - University of Cordoba & University of Seville (Spain), University College Ghent (Belgium) - revealed the effect of Humistar WG and Humistar on the reduction of leaching or soil fixation of NPK fertilizers increasing their efficacy.
Phosphorous soil fixation is a very important issue all over the world. Humistar reduces soil fixation and precipitation of P fertilizer, maintaining the added phosphorus ready for plant uptake for a longer time. Humistar also releases P fixed to soil colloids that is already present in agricultural soils, but which is usually not available for plants. The effect of Humistar is due to the sequestration of Ca, Fe or Al which otherwise form complexes with phosphates.
The chart nº 1 illustrates the results of a series of trials made at the University of Seville in 2008. The trials showed a significant effect of Humistar on maintaining P available for plants and soluble in the soil (+30%).
Nitrate lixiviation is another serious environmental problem which leads to loss of nitrogen in soils and pollution of water systems. Humistar has an excellent effect reducing the leaching of nutrients, especially on the loss of easily leached elements like nitrate. Humistar saves costs of nitrogen fertilization and at the same time improves nitrogen availability to the plants.
The chart nº 2 below shows the reduction of N leaching with Humistar on clayey soil tested in a trial at the University of Cordoba (2007). Total lixiviation was 75.7 kg/ha N for the standard treatment compared to 11.6 kg/ha N for the 25l/ha Humistar treatment and 11.8 kg/ha N in the 50 l/ha Humistar application.