Study of Effect Different Groundcover Matter on Macronutrient Content of Leaf in Integrated Apple Orchard in Eastern Hungary Pomology, Viticulture and Enology 919 Study of the Effect of Different Groundcover Matter on the Leaf Macronutrient Content in an Integrated Apple Orchard in Eastern Hungary Péter Tamás NAGY 1 , József RACSKÓ 2 , Zoltán SZABÓ 2 , József NYÉKI 2 1 University of Debrecen, Centre of Agricultural Sciences, Department of Agricultural Chemistry, Böszörményi Street138, H-4032 Debrecen, Hungary (e-mail: nagypt@agr.unideb.hu) 2 University of Debrecen, Centre of Agricultural Sciences, Institute for Extension and Development, Böszörményi Street 138, H-4032 Debrecen, Hungary Abstract Our paper investigated the effects of different groundcover materials on orchard nutrition. Trees of apple cv. 'Idared'/MM.106 (Malus domestica Borkh.) were planted into lowland chernozem soil in the spring of 1999. Soil strips of 150 cm width were covered either with straw, different livestock manure, black plastic foil, pine bark mulch or were without cover i.e. clean cultivation as a check. Leaf and soil samples were collected for chemical analysis. It was found that all groundcover treatments induced an increase in leaf nitrogen. The P content of leaf was the highest in the control treatment both in 2005 and 2006. Leaf P increased in all treatments in 2006. Observed increase of leaf P at the control, pointed out the effect of year. In the case of applying mulch matters the measured K content of leaf was lower than the control treatment both examined years. Similarly P results it was found that the effect of year was strong in the orchard and sometimes conceals the effect of treatments. Both absolute content of nutrients and their ratios pointed out that the nutrient supply of the examined soil was not optimal. Applied treatments affected leaf macronutrient status strongly but this effect was inconsistent across treatments and hided by the effect of year. Key words: apple, groundcover, soil and leaf analysis, macronutrients, nutrient uptake Introduction Although, the practise of mulching, well known to horticulture, and its importance is growing in the last few decades (Skroch and Shribbs, 1986), there are only little information about its application and its effects on orchard nutrition in Central Europe. The aim of present paper is to study the effect of different groundcover methods on macronutrient contents of apple leaf. Several publications pointed out that mulching has a positive effect on the water and temperature regime of soil and it has nutritional and biological factors as well. Nowadays the number of events of irregular weather has growing due to the global climatic change (Lakatos et al., 2005). It is very important that the productivity and the available nutrient supply of soil are improved among these climatic conditions. Based on study of Merwin et al., (1994) and Merwin and Stiles (1994) it looks mulching is an effective tool to achieve mentioned goals mostly in organic production system where the useable nutritional tools are restricted and the consumer demands are high. Proceedings. 43 rd Croatian and 3 rd International Symposium on Agriculture. Opatija. Croatia (919- XXX) ORIGINAL SCIENTIFIC PAPER Proceedings. 43 rd Croatian and 3 rd International Symposium on Agriculture. Opatija. Croatia (919-923) ORIGINAL SCIENTIFIC PAPER