MACROELEMENTS CONCENTRATION IN PLUM TREE LEAVES AND SOIL IN RESPONSE TO ORCHARD FLOOR MANAGEMENT

The aim of the study was to determine the influence of various methods of orchard floor management on extractable mactronutrients concentration in plum leaves and orchard soil. Study carried out between 2013 and 2015. Standard mineral fertilization on experimental plots was applied. Trees of ‘Valjevka’ plum (Prunus domestica L.), grafted onto Myrobalan seedlings (Prunus cerasifera Ehrh. var. divaricata Ledeb.), were planted in the spring of 2008. From 2009 to 2015, the following methods of soil cultivation under tree canopies were introduced: control with limited weeding around tree trunks; spraying with foliar herbicides; mulching with organic waste, i.e. straw with compost; mechanical soil cultivation with the use of rotary cultivators and hoe; weed mowing. The method of soil cultivation had influence on leaf concentration of phosphorus, potassium, magnesium and calcium, as well as soil concentration content of phosphorus, potassium, and magnesium in particular years of the study or as three-year mean. Orchard floor management did not affect leaf nitrogen concentration in any way. The results showed that regular weed control in the evaluated type of orchard is not necessary for properly supplying plum trees with macronutrients.

Effect of Organic and Chemical Fertilizer Application on Apple Nutrient Content and Orchard Soil Condition

Apple cultivation in Japan typically involves the use of chemical fertilizers and pesticides which can damage the environment. Therefore, in this study we investigated the orchard soil biochemical characteristics as well as the fruit nutrient contents, and pesticide residues of apples grown either organically (organic fertilizers + reduced pesticides) or with conventional chemical fertilizers and pesticide rates. Compared with conventional chemical fertilizer treatment, the organic fertilizer treatment produced fruit with significantly higher contents of sugar, as well as soil with higher total carbon, total nitrogen, and total phosphorus. There were also significantly greater soil bacterial biomass and N circulation in the organically fertilized treatments. Minimal pesticide residues were detected in the organically fertilized fruits, but in the apples cultivated with conventional rates of fertilizers and pesticides there were significantly higher levels of propargite that was used to control spider mites. These residue levels from the conventionally fertilized orchards exceeded European and Codex residue standards. These results indicate that environmentally friendly arboricultural soil management practices, such as organic fertilizer and reduced pesticide cultivation can enhance nutrient cycling in soil, reduce the burden on the environment, and promote food safety and security.

Cattle Horn Shavings: A Possible Nitrogen Source for Apple Trees

The circular economy concept promotes the recycling of agricultural waste. This study was aimed at investigating the effects of cattle horn shavings on apple tree nitrogen nutrition. Ligol apple trees on P 60 rootstock were the object of the study. The experiment was conducted in the experimental orchard of the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, from 2015 to 2018. Two fertiliser rates were tested: 50 and 100 kg/ha N. Horn shavings (14.1% N) were applied at the end of autumn or at the beginning of vegetation in the spring and in one treatment 100 kg/ha N rate was divided into two equal parts and applied both in autumn and spring. The effects of the horn shavings were compared with the effects of ammonium nitrate (34.4% N) and the unfertilised treatment. The lowest mineral nitrogen content was found in the unfertilised orchard soil and the soil fertilised with horn shavings in the spring at 50 kg/ha N equivalent. In all other cases, the fertilisers increased the soil’s mineral nitrogen content. The lowest leaf nitrogen content was found in apple trees that grew in the unfertilised orchard soil or soil fertilised in the spring with 50 kg/ha N of horn shavings (1.58–2.13%). In other cases, leaf nitrogen content was higher (1.77–2.17%). The apple trees with the lowest leaf nitrogen content produced the smallest average yield (34.5–36.6 t/ha). The highest yield was recorded from fruit trees fertilised with 50 kg/ha N of ammonium nitrate applied in spring or horn shavings applied in autumn (42.4 and 41.4 t/ha, respectively). The influence of horn shavings on the other studied parameters was similar to that of ammonium nitrate. Horn shavings, like nitrogen fertiliser, could facilitate nitrogen nutrition management in apple trees, especially in organic orchards, where the use of synthetic fertilisers is prohibited.

Effects of colloidal manure DOM on the transport of antibiotics in calcareous soils

<p>Colloids in the environment are defined as suspended particles in the size range of 1 nm to 10 microns. Both organic matter and antibiotics leached from animal manures applied to farmland may pose a pollution risk of groundwater. Manure colloids, which are mainly composed of dissolved organic matter (DOM), have been known to play an important role in facilitating transport of various strongly-sorbing contaminants in subsurface environments. Research on co-transport behavior of manure colloid DOM and antibiotics is lacking. In the present study, the effects of colloidal DOM derived from pig manure and chicken manure on the transport of different antibiotics were examined in a cropland soil and an orchard soil. According to the breakthrough curves obtained for repacked soil columns (2.5 cm in diameter, 15 cm in height) under a simulated rainfall intensity of 20 mm/h, florfenicol was highly mobile and leached out almost simultaneously with the water flow tracer Br<sup>–</sup> for the cropland soil, which exhibited an 11%-23% higher leaching capacity than for the orchard soil. On the other hand, norfloxacin and tylosin did not penetrate through the column and most of their residues were retained in the top soil layer. Pig manure DOM delayed the breakthrough of florfenicol by 0.07-0.13 pore volume and increased its residues by 15%-26% as a result of enhanced retention through a co-sorption mechanism, and similar effects of chicken manure DOM were observed.</p>

The application of biomodified fertilizers as a way to increase the effective fertility of orchard soils

The crucial trend in the intensification of gardening is the use of agrochemicals, including the systematic application of mineral fertilizers, regulated by the production flow chart of fruit products. Technological pressure on the soil causes aggravating the ecological problem of loss of the fertility level in the conditions of the orchard monoculture. The search for sustainable and environmentally effective approaches to solving the problem of managing fertility factors is aimed at studying the effects of biological and biomodified fertilizers. The changes in the main indicators of the effective fertility of the structural-metamorphic agrosem in the conditions of the orchard monoculture with the application of biomodified organo-mineral fertilizer were studied in dynamics. The prolonged effect of organo-mineral fertilizer on increasing the content of the main indicators of effective fertility in the soil was determined six years after application. The use of biomodified organo-mineral fertilizer in the orchard fertilization system is considered as an element of an integrated strategy for the management of orchard soil fertility.