DRIS (Diagnosis and Recommendation Integrated System) analysis was applied to fast-growing sweetgum (Liquidambar styraciflua L.) plantations in the southeast United States as a tool for nutrient diagnosis and fertilizer recommendations. First, standard foliar nutrient ratios for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were established using high-yield stand...

Abstract Fertilizer-N strongly limits non-leguminous crop yields; however, sweet potato ( Ipomoea batatas ) is an exception, likely due to its ability acquire atmospheric N 2 via endophytic diazotrophs. Using Raman spectroscopy, we found that in 15 -fed potato, some bacteria contained N, providing direct evidence of fixation planta . To assess -fixing capability, pot experiments were conducted ...

The experimental was split plot in a randomized complete block design with three replications. In this experiment, different levels of nitrogen in the main plots included four levels (0, 50, 100 and 150 N) kg.ha-1 urea and wheat varieties, including cultivars, Sepahan and SW were placed in the subplots. Results showed that nitrogen fertilizer and cultivar were significant effects on ...

Annual nitrogen (N), phosphorus (P), and potassium (K) flows in agriculture in The Netherlands were identified and quantified in 1990, with special emphasis on pig production. Also, the effects that various management strategies in pig production have on NPK emission in 1990 were compared using a static deterministic simulation model. Ammonia emission from pig production in 1990 (60.9 Gg N) exc...

Abstract Accumulation of high level nitrate (NO 3 ? ) in leaves is a serious issue for vegetable crops like lettuce ( Lactuca sativa L.). Therefore, this study aimed to limit NO by adjusting the balance between fertilization and irrigation program lettuce. In strip plot design with three replicates, plants were grown under four fertilizer treatments regimes. Three organic fertilizers (biochar, ...

The composition and structure of humic acid (HA) can be affected by fertilization, but the short-term effects are difficult to detect using traditional analysis methods. Using a 35-year long-term experiment in Black Soil, the molecular structure of HA was analyzed with Fourier transform infrared spectroscopy (FTIR), 13C nuclear magnetic resonance spectroscopy (NMR), and fluorescence spectroscop...

this research was conducted on determination of better planting distance and better amount of nitrogen and phosphorus for hybrid rice (bahar 1). planting distance were used in this experiment, include 30×15, 30×20 and 30×25 cm as main factor. and also nitrogen fertilizer was used, include four levels, 65, 95, 125 and 155 k/ha and phosphorus fertilizer used include tow levels, 50 and 100 k/ha as...