Laboratory and greenhouse experiments were carried out to study the effects of the fertilizer salts, NH 4 NO 3 , ammonium nitrate-limestone, (NH4) 2 SO 4 , urea, KC1, K 2 SO 4 , superphospate, and triple superphosphate, on the germination of corn, winter wheat, and their common weed species (ABUTH and AMARE for corn and GALAP and MATIN for wheat). Increasing rates of fertilizer salts from 10, 100, and 1,000 ppm were applied in five replicates in both laboratory and greenhouse experiments on 0.5 kg of a loamy soil. In the laboratory experiments, seeds were germinated on top of paper at 22°C. Germination of winter wheat seeds was inhibited only by the highest dose of urea, while that of its weed species was highly affected by the applied fertilizers. Germination and emergence of corn was only slightly affected by the fertilizer salts. Significant changes in germination of AMARE could be observed with each fertilizer salt and each concentration; these changes tended to be positive even with the highest level of superphosphates. Emergence of ABUTH was only slightly affected by the lower rates of fertilizers while it was significantly reduced by higher doses of nitrogen (N) fertilizers. Results of these studies may serve as means of integrated weed control.
Nutrient management practices that concurrently improve soil properties and yield are essential for sustaining barley production. This study was conducted to evaluate the impact of balanced nitrogen fertilizer application involving farmyard manure (FYM) and residue management. The experiment had a factorial arrangement of five levels of mineral N and two organic fertilizer sources. The five levels of N fertilizer were applied in three replicates in combination with each of the two organic sources and a control (without organic source). Average plant height (PH), grain yield (GY), and straw yield (SY) were significantly (P <0.05) influenced by the main effect of N application and organic source; however their interaction was insignificant. The highest grain yield (103%) was obtained with 120 kg N compared to the control. The grain yield increased by 23.4% and 44% with FYM and residue, respectively, against the untreated control.
Potassium (K) fixation plays a significant role in the soil-plant system influencing the effectiveness of fertilizaiton. Among the factors controlling fixation capacity of soils, clay mineralogy and soil moisture are of primary importance. The objective of this experiment was to study tbe K fixation capacity of different soil types and K levels as well as to develop quantitative relationships between amounts of exchangeable K and fixation under wet and dry conditions. Soil samples were collected from seven sites of national multi-location long-term fertilization trials representing different soil properties and K levels (i.e. clay content, clay minerals, and plant-available K). At higher K fertilizer rates, exchangeable K was higher, and as a consequence, lower wet K fixation capacities were obtained. On the other band, higher values in dry fixation of K were observed with higher K fertilizer rates. A good correlation was obtained between dry K fixation capacity of the soils and ammomium acetateexchangeable K in soils having more than 20% clay. By contrast, a lower correlation was obtained between wet and dry fixation capacities. Relationships between clay mineralogy and fixation capacities were also studied in this experiment.
Corn (Zea mays L.) leaf weight, leaf P concentrations at flowering stage, 0.01 M CaCl 2 -, Olsen-, LE-, and AL-soluble soil P contents were determined in a network of uniformed 27-year-old Hungarian long-term field trials (the so-called National Longterm Field Trials, NLFT) with four P fertilization rates on nine locations, representing various agro-ecological and soil conditions of the country.A 4 -5 fold increase in soluble P contents was found in all soil P-tests, while the absolute values of dissolved P varied greatly (CaCl 2 -P: 0.1 -3.7; Olsen-P: 3.7 -47.7; and AL-P:
3085Soil and plant P analyses data proved to be useful tools in adapting the results of long-term field trials for improved, environmentally sound fertilizer recommendations.
CONCLUSIONSThe correlation between Olsen P and corn leaf P indicate that both methods are suitable for evaluating soil and corn P status under the agro-ecological conditions of Hungary. Soil test methods less dependent of soil texture and reaction status show better correlation with plant P contents and responses to P than methods more dependent.Soil and plant P analyses data are useful tools in adapting the results of long-term field trials for developing fertilizer recommendations.
ACKNOWLEDGMENTSThe scientific board for planning and development of the the experiments included Professors G. Láng (chairman), E
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.