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Effect of crop residues on soil aggregate stability
23-32Views:92Soil structure may be improved by adding readily decomposable organic matter. The extent of amelioration depends on the chemical build-up and decomposability of the crop residues. Three different kinds of organic matters were investigated: (1) maize stem, (2) wheat straw, and (3) maize stem
& wheat straw. Comparing the aggregate stabilizing effects of the differently decomposable organic matters to each other, the expected maize stem & wheat straw (mw) > maize stem (m) > wheat straw (w) order was proved. -
The aggregate stability of the soil in respect to the uniform aggregate stability indicator
83-99Views:86Soil structure and its quality are fundamental properties because they control many processes in soils. Tillage, crop and other factors influence soil structure. Efficient protection of it needs indication of changes in soil structure. A new Normalized Stability Index proposed by Six et al. (2000) tries to evaluate these changes, which was compared with some former used indices. The most common method (wet sieving) was modified to reduce the confounding effects of different particle size distribution of different soil types and method used to the investigation. Changes in soil structure caused by tillage and crop management therefore have been made quantitative and comparable. In this paper, we review the new method and Normalized Stability Index proposed by Six et al. (2000) and present the results of our investigations.
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Inhibition of the spread of Sclerotinia sclerotiorum in aquaponics
5-8Views:200Sclerotinia sclerotiorum, which causes white mold, is a widespread pathogen. In 2020, a new host plant of this fungus, the watercress (Nasturtium officinale) was identified in Hungary in an aquaponic system. During the cultivation of watercress S. sclerotiorum was detected on the plant, the fungus caused a 30% yield loss. Fungicides should not be used against fungi in aquaponic systems. Non-chemical methods of integrated pest management should be used. These include biological control (resistant species, predators, pathogens, antagonist microorganisms), manipulation of physical barriers, traps, and the physical environment. In the aquaponic system, the removal of the growing medium (expanded clay aggregate pellets) solved the damage of Sclerotinia sclerotiorum 100%. By removing the expanded clay aggregate pellets, the environmental conditions became unfavorable for the development and further spread of the S. sclerotium fungus.
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Assessing of soil aggregate stability: the sand-correction and its relevance
29-47Views:99Soil structure and changes in its quality caused by Maize stem (1), Wheat straw (2) and Maize stem & wheat straw (3) addition were assessed by three aggregate-stability indices. We observed that the NSI index formula proposed by Six et al. (2000) was nonsensitive to the changes in soil structure caused by the investigated organic matter addition. Furthermore it overestimates the aggregate-stability of the investigated silty sandy loam soil. Therefore we proposed a new modified NSI formula which is sensitive to the questionable treatments and that resulted in a more
realistic NSI data. The most sensitive index to differences of the investigated treatments were the Mean weight diameter (MWD) proposed by van Bavel (1953, in Kemper és Rosneau, 1986). -
Effect of soil-compost proportion on the abiotic and biotic parameters of soilplant system
99-104Views:95The environmental awareness, coming to the front in the 21st century, motivates us to supply the plant nutrient demand (in point of the plant, the environment and the human health) with natural materials.
Composting is known since the beginning of civilization. We came to know more the processes of composting as a result of last decades’ research, but numerous unexplained questions remained up to this day. The good compost is dark gray or brown, and it should not create an odor. It has aggregate structure, and it’s pH is neutral. Compost is soil-like (Fehér, 2001), nutrient-rich material, which contains valuable nutrients extracted from soil, so if we recycle this, we can decrease the chemical fertilizer and other (example: mineral energy) expenses.
The reason of that we chose the more accurate cognition of compost utilization is to do more effective the site-specific nutrient supply. This increases the average yield and the quality of yield. Besides we can decrease the harmful effects, which endanger the plant, the environment, and the human body.
During the compost utilization experiment we blended the acid sandy soil with compost in 4 different volumetric proportions (5 treatments) than we set the pots randomized. The advantage of this method is that we can provide equal conditions for plants so we can measure the effect of treatments correctly. Our experimental plant was ryegrass (Lolium perenne L.), that grows rapidly, tolerates the glasshouse conditions, and indicates the effect of treatments well. After the harvest of ryegrass we measured the fresh and dry weight of harvested leaves and the total C-, N-, S-content of the dry matter and of the soil, we examined the pH and the salt concentration of soil as well.
Our aim was to study and evaluate the relations between the compost-soil proportion and the nutrient content of soil and plant. In our previous experiments we confirmed (based on variance analyses) that the compost has a beneficial effect on soil and increases the nutrient content of the soil (Szabó, 2009). But it’s important to appoint that the compound of compost is seasonally change: in winter the selective gathered municipal solid waste contains salt that were applied for non-skidding of roads, but salt has a negative effect to the plant. We proved that in our experiment the 25/75% compost/soil proportion was ideal for the plant. This content of compost effected 6 times higher green matter weight compared to the 100% sandy soil. -
The effect of soil cultivation systems on organic matter distribution in different grain size fractions of the soil based on three years of experience
22-30Views:71Changes in the physical distribution (particle size and the state stability against decomposition) of the organic carbon pool in tilled layers of Hungarian field soil under different tillage treatments were studied. Three years after starting the experiment, soil samples were fractionated (they were taken in March 2005) by their particle size and density. The treatments caused well measurable, significant effects on two fractions of intra-microaggregate organic matter (53-250μm particle-sized, well and less decomposition-resistant pools) and onto their relative rate in the organic carbon pool of the whole soil.
Different tillage treatments caused different distributions in the organic matter fractions. In regularly intensely cultivated soils evolve different physical structure, particle size-distribution, which reduce the soil fertility and its resistance against outer impacts. -
The effect of compost application on physical properties of sandy soil
67-70Views:150The sewage sludge compost is suitable to improve the colloid-poor sandy soils, which are common characteristics of poor water- and nutrientholding capacity. The general characteristics of sandy soils are the light mechanical composition, the low content of humus and mineral colloids, large pore size and a bad aggregate stability. They have a poor nutrient supply capacity, due to its high porosity the organic matter is degraded very quickly to mineral colloids (Stefanovits et al., 1999).
By the compost application the soil is enriched mineral and organic colloids, thereby improving the soil structure. The effect of addition of compost to soil the water- and nutrient-holding capacity and porosity could be increased and the bulk density could be decreased (Martens and Frankenberger, 1992).
The aim of our experiment is to carry out physical measurements to determine the effects of compost treatment. In this study the results of the first year are presented.