Opposite tendency between yield and taste of organic tomato by increasing biochar doses in a slightly humous arenosol

T. Kocsis¹*, Z. Kotroczó², K. Juhos²2, B. Ferschl³, V. Rozmann⁴, A. Brückner¹ and B. Biró²

¹Hungarian University of Agriculture and Life Sciences, Department of Food Microbiology, Hygiene, and Safety, Somlói Str. 14–16, H-1118 Budapest, Hungary
²Hungarian University of Agriculture and Life Sciences, Department of
Agro-Environmental Studies, Budapest, Villányi Str. 29–43, H-1118 Budapest, Hungary
³Hungarian University of Agriculture and Life Sciences, Department of Ecological and Sustainable Production Systems, Budapest, Villányi Str. 29–43, H-1118 Budapest, Hungary
⁴Hungarian University of Agriculture and Life Sciences, Department of Agricultural and Food Machinery, Villányi Str. 29–43, H-1118 Budapest, Hungary
*Correspondence: kocsis.tamas.jozsef@uni-mate.hu

Abstract:

The tomato is the edible berry of the plant Solanum lycopersicum. Tomato plants are widely grown in temperate climates worldwide and are mostly cultivated as annuals. The objective of this study was to understand the interrelation between fruit quality of tomato, some soil biological parameters, and the addition of increasing biochar (BC) soil amendment doses. BC is an industrial product, made from organic waste by pyrolysis. Its use in the soil is known to improve fertility and several soil functions. Among organic, ecological conditions, a field experiment was performed in a type of slightly humous arenosol soil. Effect of increasing doses of biochar (BC) (0.5-, 1.0-, 2.5-, 5.0, 10 m/m% and control) was studied. Nutrient content and Total Soluble Solid (TSS) of the fruits, the ripeness, and the marketable/non-marketable ratio of yield were assessed. The presence of some cultivable microbial physiological groups (fungi, bacteria) and the soil-dehydrogenase activity (DHA) was estimated. Results represented that the changes of fruit TSS content was not linear with the increasing doses of BC. The increased yield (+53%) had an inverse correlation with the TSS content of the berry’s pulps, and the content was lowest at the highest BC dose. Optimum doses of BC were considered, like 1–2.5 m/m%, supported by the nutritive element content (+55% N, +76% P, +83% K) and enhanced microbial activities (+45% DHA). Grouping the parameters by Pearson Correlation Coefficient, the biochar amendment was a driving factor for tomato growth, with certain dose limits in the studied organic agricultural practice.

Key words:

biochar, ecological farming, nutrient uptake, soil biology, tomato

Preliminary results of nitrogen uptake with mown grass in an apple orchard under influence of mulch and irrigation

V. Surikova¹, A. Kārkliņš² and E. Rubauskis¹

¹Latvia State Institute of Fruit–Growing, Graudu iela 1, Dobele, LV 3701; e–mail:Valentina.Surikova@lvai.lv
²Latvia University of Agriculture, Lielā iela 2, Jelgava, LV 3001; e–mail:Aldis.Karklins@llu.lv

Abstract:

Nitrogen leaching from intensive agriculture systems is one of the major contributors responsible for nitrate concentration increasing in groundwater. The aim of the study was to determine the content of total nitrogen in the orchard lawn and use this parameter as a correction factor for reduction of nitrogen fertilizers application and to include the nitrogen from mown grass into the N balance and turnover calculation. The investigation was conducted at the Latvia State Institute of Fruit–Growing, Dobele in 2009, on the basis of an existing field experiment planted in 1997 with cultivar `Melba` (rootstock B 9). The influence of soil moisture management treatments were compared near the alleyway: control, sawdust mulch and fertigation. The alleyway was covered by grass vegetation (Lolium perenne L. and Poa pratensis L,). Total nitrogen was determined using the Kjeldahl method. The preliminary results show that the mulch used in tree strips in an apple orchard had a significantly negative influence on the concentration of nitrogen in the dry matter of mown grass of the alleyway compared with control and fertigation. Near the mulching treatment the concentration of nitrogen in dry matter of mown grass in the alleyway was 2.23%, but near the control and fertigation treatments it was 8% higher. Nitrogen concentration in the grass of the alleyway was significantly influenced by the time of grass mowing. Nitrogen uptake with mown grass biomass in the alleyway near the control in tree strips was 33.36 kg ha-1, near the mulch treatment it was higher by 6%, but in fertigation treatment – by 20%.

Key words: