in order to study the effect of different levels of nitrogen and sulfur fertilizers on yield, yield components, content of some elements, qualitative and quantitative traits of spring safflower (serin cv.) an experiment was conducted at agriculture and natural resource research station of ardabil in 2008. this experiment was carried out in factorial experiment in completely randomized block des...

Theoretical considerations have suggested that there may be differences in photosynthetic nitrogen use efficiency (PNUE) among plants that use different biochemical variants of C(4) photosynthesis. To test this hypothesis we examined the leaf nitrogen content and photosynthetic rates of six grass species (three of C(4) subtype NAD-ME and three of C(4) subtype NADP-ME) grown over a wide range of...

In order to study the effect of zeolite and biologic fertilizers application under different irrigation regime on yield and quantitative traits in sugar beet, a research project was conducted according split-split plot experiment based on randomized complete block design with four replicates. The main factor included irrigation regime at two levels (Normal and stress), sub factor included zeoli...

Strong positive correlations between the maximum rate of canopy photosynthesis, canopy-averaged foliar nitrogen concentration, and canopy albedo have been shown in previous studies. While leaf-level relationships between photosynthetic capacity and foliar nitrogen are well documented, it is not clear whether leaf-level relationships between solarweighted reflectance and nitrogen underlie the ca...

Short fruit cucumber was chosen as object. Different nutrition conditions were applied to cultivate plants.CCD camera with special filters was used to gather images. Correlation analysis results shows that four indexes, CNDVI, GNDVI, NDGI and NDVI, had much higher correlation with nitrogen content of cucumber leaves. LS-SVM algorithm was proposed to construct models between vegetation indexes a...

Variable fertilization for crops, like corn, depends on monitoring nutrition condition. Thus, hyperspectral reflectance was used to predict chlorophyll and total nitrogen content under different N,K treatments during corn growth. The area of the experimental field was divided into 3 strips with different nitrogen treatment (N1:0 kg/ha–low, N2:314 kg/ha–normal, and N3:653 kg/ha–high). In each st...