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Microbiological and Chemical Characterization of Different Composts
106-111Views:179Composting of agricultural waste is considered particularly important from the point-of-view of environmental protection. Degradation of organic substance results in a significant reduction of waste volume.
The end product of the composting process, mature compost, can be used as soil coverage against excess loss of wastes, for mulching, for organic manure etc. The problem of composting has come into limelight in environmental studies and in agriculture.
The quality of the mature compost is determined by physical, chemical and biological parameters of the composting process which, in turn, depend on initial composition of the raw materials, the technology, e.g. regular mixing and moistening and on environmental factors. Quality is the key question in compost use.
We studied the composting process in compost windrows of different raw material composition. We measured temperature, humidity content, pH, organic substance content, nitrogen and carbon content.
We counted the number of bacteria, microscopic fungy, ammonifying and cellulose decomposing microorganisms. We directed the composting process with turning weekly (to provide oxygen) and watering (to provide humidity content 40-60%).
We set up windrows of 1 m3 volume from dry plant substances (cornstalk, pea straw, tomato stalk and crop, weeds) and cow manure not older than 1 week. The cow manure was used at ratios of 0%, 35%, 50%, 65% and 100%, respectively.
We measured changes in compost temperature relationship with outside temperature until they were almoust the same. Humidity was 40-60% in most cases.
At the beginning of the process, pH was slightly acidic-neutral; it later becomes neutral-slightly alkaline (pH: 6.93-8.02) as ammonia is liberated from proteins.
At the end of the process, pH decreased again, due to humification.
Organic substance content decreased as microorganisms mineralized them. Organic carbon content decreased gradually due to microorganisms used it as an energy.
Total nitrogen content increased until middle of july and decreased gradually until than.
The carbon/nitrogen rate were higher in the beginning, it decreased until july-august and increased by smaller degree until end of the process.
The number of bacteria was higher in the first three weeks and between june-september. The number of cellulose degrading bacteria was the highest in the first three month, the number of ammonifying bacteria was the highest from the end of may until sepember.
The number of microscopic fungy was significant in the second part of process, after july. -
Impact of fertilisation and the fluctuation of precipitation on the ecophysical and production characteristics of maize
39-44Views:559The aim of this study was to analyse the problems caused by the unfavourable (dry and wet) weather and its consequences in the R1 growth stage of maize (Zeamays L.), as well as their management and the alternatives of preventing yield reduction by using agrotechnical measures fertilisation, irrigation), also, we wanted to examine whether the Chl content measured in the R1 growth phase provides reliable prediction of yield per hectare.
The examinations were carried out in a moderately warm and dry production area at the Látókép Experiment Site of the University of Debrecen, Centre for Agricultural Sciences on calcareous chernozem soil in 2007 and 2008. Six different N doses (0,30,60,90,120,150 kg ha-1) were used in the irrigated and non-irrigated treatments of the field experiment.
The results showed that there is a significant strong positive correlation between Chl content and yield both in the non-irrigated (P<0.001, R=0.777) and the irrigated (P<0.001, R=0.801) treatment. The results of the correlation analyses performed yearly showed that weather factors significantly influence the strength of correlations, but these correlations are always positive.
The Chl content of maize leaves provided a reliable prediction of yield per hectare in the R1 growth stage. In the irrigated treatment, the correlation is always closer than in the non-irrigated treatment.
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Productivity and Nutrient Reaction of Maize Hybrids
78-83Views:376Several factors influence the quantity and stability of maize yield, the most important being the nutrient supply, the hybrid and precipitation. In 2004, during the maize growing season the precipitation was more than the 30 year’s average, with 68.3 mm, but the distribution was unfavorable. The experiment was carried out in Debrecen at the Experimental Station of the University of Debrecen Centre of Agricultural Sciences, Department of Crop Production and Applied Ecology. We tested 10 various hybrids with their own genetic characteristics for five different fertilizer doses, in addition to the parcels without fertilization.
The favorable results reached were due to the rainy season. The average yield varied between 7.78-9.67 tha-1. The DK 440, PR37M34, PR38A24, PR39D81 and PR36R10 of the hybrids reacted to higher fertilizer doses with significant growth yields, the yield (more than 11 tha-1) was the highest for N200, P125, K150 fertilizing. The other hybrids, DKC 5211, Mv Vilma and MV Maraton, gave similar results at the N120+PK fertilizer dose and the ensuing doses depressed the yield. Fertilization was more effective thanks to the precipitation. The fourth and fifth dose increased or decreased maize yield depending on the nutrient reaction of the hybrid. The agro-ecological optimum of NPK fertilization was N120, P75, K90 kgha-1.
During the experiment we tested the moisture loss of five hybrids. The rainy crop year’s effect on the seed moisture content at harvest was higher than in previous years. The seed moisture content hybrids at harvest which have shorter crop years (FAO 300) was 18-19%, and hybrids with longer vegetation periods had more than 20% seed moisture content. DK 440 hybrid had the intensive moisture loss of the five hybrids, at the start of the measurement, the seed moisture content was higher than 40%, and it decreased to 18.6% by harvesting.