Effects Of Different Fertilizer Treatments Research Articles

Simulation of nitrate leaching for different nitrogen fertilization rates in a region of Valencia (Spain) using a GIS–GLEAMS system

Abstract The groundwater loading effects of agricultural management systems (GLEAMS) model coupled to a GIS was used to evaluate the effect of different fertilization treatments on the total N leaching in a selected area of eastern Spain with intensive agriculture. Four nitrogen fertilization rates (traditional or base, base rate reduced by 20%, reduced by 50%, and the rate calculated by the Nmin recommendation system for vegetables, and reduced by 70% for citrus) were evaluated at a regional scale to find the rate that minimized N leaching without reducing crop N uptake. Nitrate leaching maps were obtained for the different nitrogen rates studied. A great reduction of N leaching (up to 68% for vegetables, and 75% for citrus) was observed under the most reduced fertilization rates and this reduction was greater in areas irrigated with surface water in comparison to those irrigated with groundwater. The GIS–GLEAMS system was a useful tool to assess the N leaching at a regional scale for the different N management considered. For example, it was shown that the Nmin recommendation system was the most efficient for vegetables, and for citrus the most efficient fertilization rate was the reduced 50%, that is similar to that recommended by the Code of Good Agricultural Practices. The areas irrigated with groundwater with high nitrate content had a high leaching rate, and the nitrate applied in irrigation water should be considered when planning the crop fertilization. A temporal analysis of the NO3-N in soil, N leaching, crop evapotranspiration and rainfall allowed to identify the influence of the soil NO3-N and the rainfall on nitrate leaching.

Effects of different fertilizer treatments on ectomycorrhizal colonization potential in two Scots pine forests in Sweden

Ectomycorrhizal fungal colonization potential was studied in two low- productivity Scots pine ( Pinus sylvestris L.) forests in Sweden treated with different fertilizers. Young Pinus sylvestris seedlings were used as baits for ectomycorrhizal fungi for one growing season and the total ectomycorrhizal colonization level and frequencies of different types were recorded. One of the experimental sites had been fertilized once with 600 kg nitrogen (N) ha −1, either as ammonium nitrate or urea, 13 years previously. At this site no difference in the total number of ectomycorrhizal root tips was found between the different treatments and approximately 70% of all root tips were ectomycorrhizal. The other experimental site had been continuously fertilized for 15 years with a balanced nutrient mixture, applied either daily as a solution (IF treatment), or as solid fertilizers once a year (F treatment). The IF treatment had received 1700 kg N ha −1 and the F treatment 950 kg N ha −1 until our study was conducted. At this site a significant decrease in total ectomycorrhizal infection level was found as an effect of the fertilizer treatment. In the non-fertilized plots, 70% of all root tips were ectomycorrhizal and the corresponding figure for fertilized plots was 55%. At both sites the frequency of one of the eight classified ectomycorrhizal types decreased significantly in all fertilized plots except in the urea treatment.

Studies on“Ijoyo”(abnormal leaves) developed in a certain training system of Nijisseiki pears. III.

1. Effects of different fertilizer treatments and soil managements on the growth of trees and their development of abnormal leaves were observed with Nijisseiki pears planted in the field. Growth was much promoted by nitrogen application, but not so much by phosphate, potash, lime and magnesia applications. It was also somewhat promoted by mulching, and slightly retarded by sod culture. Abnormal leaves (so-called ljoyo) developed greatly in the third year after planting, regardless of the kinds of fertilizer treatments and soil managements.2. On the other hand, when observed with plants grown in the pots of large size, growth was greatly promoted by applications of the three nutrients, in the order of nitrogen, phosphate and potash. With increased applications of nitrogen, leaf contents of N and Mg increased and that of K decreased. With increasing phospate application, leaf contents of P and Mg increased. As the application amount of potash was increased, the leaf content of K increased and those of N, Ca and Mg decreased. In the third year after planting, abnormal leaves developed in most of plots except for nonfertilizer, non-nitrogen and non-phosphate, though very slightly in the non-potash plot.3. In the both experiments above mentioned, the longer the shoot length, the more extremely abnormal leaves seemed to develop in the following year, having no connection with fertilizer treatments.

Electrodialysis of Soils: III. Effect of Different Fertilizer Treatments of Soils on the Bases and Acids Extracted by Electrodialysis1

Agronomy JournalVolume 20, Issue 11 p. 1141-1159 Article Electrodialysis of Soils: III. Effect of Different Fertilizer Treatments of Soils on the Bases and Acids Extracted by Electrodialysis1 Harry Humfeld, Harry Humfeld Formerly Research Fellow in Soils, Iowa State College; now Assistant Bacteriologist, Bureau of Chemistry and Soils, U. S. Department of Agriculture, Washington, D. C. The writer takes this opportunity to thank Dr. P. E. Brown of the Soils Section of the Department of Farm Crops and Soils of the Division of Agriculture, Iowa State College, Ames, Iowa, for reading and editing the manuscript, and Dr. Paul Emerson of the Soils Department for valuable and helpful suggestions while he was conducting the studies reported in this manuscript.Search for more papers by this author Harry Humfeld, Harry Humfeld Formerly Research Fellow in Soils, Iowa State College; now Assistant Bacteriologist, Bureau of Chemistry and Soils, U. S. Department of Agriculture, Washington, D. C. The writer takes this opportunity to thank Dr. P. E. Brown of the Soils Section of the Department of Farm Crops and Soils of the Division of Agriculture, Iowa State College, Ames, Iowa, for reading and editing the manuscript, and Dr. Paul Emerson of the Soils Department for valuable and helpful suggestions while he was conducting the studies reported in this manuscript.Search for more papers by this author First published: 01 November 1928 https://doi.org/10.2134/agronj1928.00021962002000110002xCitations: 2 1 Contribution from the Department of Farm Crops and Soils, Iowa State College, Ames, Iowa. Part of a thesis submitted as partial fulfillment for the requirements for the degree of doctor of philosophy, Iowa State College. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume20, Issue11November 1928Pages 1141-1159 RelatedInformation