Lysimetric research of nutrient losses from organic fertilizers

L. Česoniene¹ and V. Rutkoviene²

¹Institute of Environment, Lithuanian University of Agriculture. Studentų 11, LT-53356,Kaunas-Akademija, tel./fax. +370 37 752 202; e-mail: laima.cesoniene@lzuu.lt.
²Institute of Environment, Lithuanian University of Agriculture. Studentų 11, LT-53356,Kaunas-Akademija, Kaunas district. Lithuania, tel./fax. +370 37 752 202;e-mail: vida.rutkoviene@lzuu.lt

Abstract:

In organic agricultural production high quality and safe agricultural products and foodstuffs are produced. It is believed that organic fertilizers are slower to wash out into water, because their mineralization is slow and hence water contamination with nitrogen compounds is smaller. The aim of this research is to assess the migration of nitrogen compounds in the soil-water system after application of organic fertilizers. The investigations were performed in an established site of eight lysimeters. They are filled with monoliths of equal soil. In July, plants growing in the lysimeters were fertilized with the following organic fertilizers: Biokalis, Biojodis, Provita, Horn Shavings, Horn Core Powder and different amounts of slurry. No fertilizers were used in lysimeter No. 8. Water quality parameters NO+2¯, NO3¯ and NH4 valueswere determined. Results show the influence of different organic fertilizers on the dynamics of nutrients in soil- water systems.

Key words:

The effect of cultivation methods on the yield and biological quality of potato

M. Järvan and L. Edesi

Department of Plant Sciences, Estonian Research Institute of Agriculture, Teaduse St. 13,EE75501 Saku, Estonia; e-mail: malle.jarvan@eria.ee

Abstract:

The effect of organic and conventional methods on the yield and biological quality of potato in two field crop rotations was identified. The field trials were performed in Central-Estonia in Olustvere (58º 33΄ N, 25º 34΄ E) during two years and in North-Estonia in Saku (59º 18΄ N, 24º 39΄ E) during three years. In Olustvere the following cultivation methods were compared: organic I – without manure, organic II – with cattle manure (at the rate 60 t ha-1), and conventional (manure, mineral fertilizers and pesticides were used). In organic cultivation the fertilization with manure increased the potato yield on average 36.5%. At that, the dry matter content in tubers decreased and the nitrate content increased. In conventional farming the yield was 127% higher than in the variant organic II. In organic cultivation the tubers’ content of dry matter, starch and minerals was higher than in conventional cultivation. As to the content of reducing sugars, crude protein and nitrates no significant differences were found between the cultivation methods.In Saku, the yields and biochemical composition of potato were compared in trial areasfertilized with plant compost and mineral fertilizers. Equivalent rates of NPK to both trial variants were applied during three years. With compost the yield of potato was on average 32.1% lower than with mineral fertilizers. There were no significant differences in the effect of compost and mineral fertilizers on the biological quality of potato tubers.

Key words:

crude protein, equivalent rates of NPK, minerals, nitrates, organic and conventional cultivation, reducing sugars, starch