Fertilizer-intensive soya bean agriculture has recently expanded in southeastern Amazonia, and whereas intensive fertilizer use in the temperate zone has led to widespread eutrophication of freshwater ecosystems, the effects in tropical systems are less well understood. We examined the fate of fertilizer phosphorus (P) by comparing P forms and budgets across a chronosequence of soya bean fields...

To evaluate the process of nitrate accumulation and leaching in surface and ground water, we conducted simulated rainfall experiments. The experiments were performed in areas of 5.3 m2 with bare slopes of 3° that were treated with two nitrogen fertilizer inputs, high (22.5 g/m2 NH4NO3) and control (no fertilizer), and subjected to 2 hours of rainfall, with. From the 1st to the 7th experiments, ...

A 2-year study was done to compare the effects of nitrogen (N) fertigation and granular fertilizer application on growth and availability of soil N during establishment of highbush blueberry (Vaccinium corymbosum L. "Bluecrop"). Treatments included four methods of N application (weekly fertigation, split fertigation, and two non-fertigated controls) and four levels of N fertilizer (0, 50, 100, ...

The use of the 15N label for agronomic research involving nitrogen (N) cycling and the fate of fertilizer-N is well established, however, in the case of long term experimentation with perennial crops like citrus, coffee and rubber tree, there are still shortcomings mainly due to large plant size, sampling procedures, detection levels and interferences on the system. This report tries to contrib...

It is of great concern worldwide that active nitrogenous gases in the global nitrogen cycle contribute to regional and global-scale environmental issues. Nitrous oxide (N2O) and nitric oxide (NO) are generally interrelated in soil nitrogen biogeochemical cycles, while few studies have simultaneously examined these two gases emission from typical croplands. Field experiments were conducted to me...

The rising fertilizer use accompanying more people eating more has been called exponential (1) and prompted fears of polluted water and consequent methemoglobinemia (2) and hypoxia (3). It also has raised alarm about greenhouse warming (4) and an altered global N cycle and thus primary production (5) and diversity (1) of vegetation. In this plethora of issues we concentrate on a few, beginning ...

a split plots experiment based on randomized complete blocks design was carried out at field research center of islamic azad university, shoushtar branch during 2012 to find out the suitable sowing date and urea fertilizer used in chamomile (matricaria recutita). main plots including three sowing date (9, 19 and 29 february 2012) and subplots including four levels of urea fertilizers (5, 10, 15...

In order to evaluate the different growing media and nitrogen fertilizer (urea) on some morphological traits of Spathiphyllum plant, an experiment was carried out in split plot arrangement based on completely randomized design in three replications in greenhouse conditions in 2018. The main plot consisted of different growing media including T1: Leaf-mold, T2: Vermicompost and T3: A mi...

The growth and yield of Egusi melon in response to application of an Organo-mineral fertilizer was investigated. The Organo-mineral fertilizer was Cow-dung generated from an Abattoir fortified with inorganic Nitrogen. The fertilizer had a pH of 6.1; 61.2 g kg Organic Matter; 35.5 g kg -1 -1 Organic Carbon; 3.6g kg Nitrogen; 372.54 mg kg Available Phosphorus and 14.8cmol kg -1 -1 -1 Exchangeable...

A variable rate fertilizer system was developed for control of fertilizer amount by optical sensor measured NDVI of crop. The paper analyzes the input and output conditions of control system, and designed hardware, algorithm and control of fertilizer, mainly software flow and a feedback control way. In the paper, the variable-rate control system consisted of 6 optical sensors mounted on a boom ...