Search
Search Results
-
Drought-induced Losses in Fruit Orchards
37-40Views:75Scientists investigating the causes of the extremities of climate that have become quite frequent in the Carpathian Basin over the past few years are quite often in doubts as to whether increased atmospheric warming and the shortage of rainfall are to be seen as recurrent natural phenomena under our climate, or the first signs of global warming. Climate anomalies have, to a certain extent, always been common in the Carpathian Basin. However, statistical data of the past few decades indicate that the rise in temperature and the fall in precipitation have, by now, become a tendency, which requires further in-depth scientific research.
The series of articles to be published in continuation of this paper endeavors to synthesize the research results and many years of experiences, in order to give an analysis of
I. The economic effects and the symptoms of drought in tree cultures
II. The possibilities of reducing the adverse affects of drought -
The irrigation influence under the soil, microclimate and plants in maize from Crişurilor Plain
180-186Views:71The paper is based on the researches carried out in the long term trial placed on the preluvosoil from Oradea in 1976, for establishing
the soil water balance. In the irrigated variant the soil moisture was determined 10 to 10 days for maintaining the soil water reserve on
irrigation depth (0 – 50 cm for wheat and bean, 0 – 75cm for maize, sunflower, soybean, sugarbeet, potato and alfalfa 1st year and 0 – 100
cm for alfalfa 2nd year) between easily available water content and field capacity. Thus, an average irrigation rate of 2560 m³/ha was used
in the 9 experimental crops. The average of the annual rainfall for the 1976 – 2008 period was of 625.0 mm. The technologies used were
correlated with the needes of the crops, such as melioration crop rotation, chemical fertilizers in accordance with the chemical export on the
yield, manure (40 t/ha) was used in potato and sugarbeet. After 33 years of the irrigation use the soil structure degree (38.62%) did not
decrease when compared to the unirrigated maize – wheat crop rotation (37.01%). Bulk density, total porosity, penetration resistance and
hydraulic conductivity have worse values than the ones in the unirrigated variant. The humus content is very close to the humus content
determined in 1976, the phosphorus and the potassium content increased very much in comparison with the initial content (117 ppm vs 22.0
ppm); (180.0 ppm vs 102 ppm). The use of the adequate fertilization system and of the irrigation water with a good qaulity did not determine
a decrease of the pH value of the soil. The irrigation determined the improve of the microclimate conditions, the increase of the plant water
consumption, yield gains very significant statistically and higher protein content of the maize grains. -
Effect of Soil Covering on the Soil Enzyme Activity of Integrated Orchard
20-29Views:82The purpose of our experiments is to discover the effect of different soil cover matters (agrofoil and black polyethylene) on the activity of some enzymes (phosphatase, saccharase, urease, catalase, dehydrogenase) occuring in soil. Soil samples were taken from a cider apple plantation of the Fruit Producing Research and Advisory Kht Újfehértó. The enzyme activity was measured according to Krámer and Erdei (1959a), Kuprevič and Tsherbakova (1956), Kuprevič et al. (1966), Frankenberger and Johanson (1983), Mersi and Schinner (1991). Soil moisture content was by conventional (drying chamber) method measured during every sampling and enzyme activity was transpolated to absolute dry soil. Results were estimated by mathematical methods (variation analysis, correlation counting). Soil samples were taken by trials 5 times (in every two months) a year in the vegetation period from March to November.
By recording the monthly changes of the enzyme activity we have observed the following. The activity of the phosphatase was generally the highest in May and the lowest in November. Depending on the trials, high values were also measured in March and September. The activity of the saccharase was generally the highest in November and the lowest in June, but at the same time peaks even occured in May and September. The highest urease avtivity was measured in September and November, and the lowest activity in May and July, also depending on the trials. In the year 2000, after a deep point in March, the activity of the catalase was the highest in November or by certain trials in September. In 2001, the lowest activity was also measured in March, but the highest activity appeared in November in case of one-minute trial, and in May in consequence of two-minute trial. Finally the activity of dehydrogenase was the highest in November and the lowest in July apart from the model years.
There were essential differences in rainfall of the two experimental years which was reflected in the enzyme activities. There was a poor positive significant relationship between soil moisture content and enzyme activity values in case of phosphatase, saccharase, urease (r=0,426; 0,480; 0,396) respectively. In case of catalase1 (r=0,518), catalase (r=0,556), dehydrogenase (r=0,559) we obtained a medium strong positive relationship between soil moisture content and enzyme activity values. By evaluating the effect of different trials in case of every examined enzyme significantly higher values were detected in soils covered by agrofoil (a porous black polyethylene) than in soils covered by black polyethylene or in uncovered soils. Moreover, the soil covered by black polyethylene showed significantly higher enzyme activities (besides phosphatase) than the control soil. Thus soil-covering meant statistically significant advantages in enzyme activity as opposed to uncovered soil proved. -
The effect of compost made of sheep manure on the first cut of a semi-natural grassland
25-29Views:188In an experiment, two types of compost were tested on natural grassland in order to improve the productivity of a natural sward on solonetz soil. Both composts were made of on-farm produced sheep manure, but the second one was enriched in phosphorus. These fertilizers/composts are officially authorized and can be applied in organic farming. Zero application and three rates of fertilizer were tested (10 t ha-1, 20 t ha-1, 30 t ha-1) on 30 m2 experimental plots wit four replications. Dry matter, crude protein and net energy content for maintenance were measured and determined and their yields per unit area were calculated. We found that all the treated plots produced significantly higher yield than the control ones, and in some cases the yields were almost three times higher. However, the optimal compost dose varied, depending on the examined parameter. Based on the evaluation of the experiment results along with rainfall data, it was concluded that, with higher precipitation, the positive effect of the compost application was bigger. The difference between the natural and enriched compost is remarkable, but it has to be mentioned that even the natural compost showed good results; therefore, it is also effective in improving the fertility of grassland.