Portable Chlorophyll Meter for Indirect Evaluation of Photosynthetic Pigments and Nitrogen Content in Sweet Sorghum

Efficient nutrient management requires estimating factual fertilizer requirements. This study was aimed to test the use of chlorophyll meter SPAD-502 to estimate the nitrogen status of tea maintenance leaf. The test was carried out by correlating the SPAD readings with destructively measured leaf nitrogen content using samples oGbtained from nitrogen fertilizer dosage experiments. Observations were made at 15, 32, 45 and 62 days after the application of N fertilizer treatments. The results showed that the SPAD readings and total nitrogen leaf content correlated significantly with the time of observation. Estimation of leaf N content based on the SPAD readings follows linear line equation y = 0.0311x + 1.5856 with coefficient determinant (R²) = 0.62 significantly at P less than 0.01. It was concluded that SPAD-502 chlorophyll meter is reliable to assess the leaf nitrogen content of tea maintenance leaf and is adequate to predict future nitrogen fertilizer requirements.

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Growth seasonality, photosynthetic pigments, and carbon and nitrogen content in relation to environmental factors: a field study of Ulva olivascens (Ulvales, Chlorophyta)

Phycologia ◽

10.2216/i0031-8884-39-1-50.1 ◽

2000 ◽

Vol 39 (1) ◽

pp. 50-58 ◽

Cited By ~ 42

Author(s):

María Altamirano ◽

Antonio Flores-Moya ◽

Francisco Conde ◽

Félix L. Figueroa

Keyword(s):

Environmental Factors ◽

Nitrogen Content ◽

Field Study ◽

Photosynthetic Pigments ◽

Carbon And Nitrogen ◽

Carbon And Nitrogen Content

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Chlorophyll Meter Method For Estimating Nitrogen Content In Plant Tissue

Handbook of Reference Methods for Plant Analysis ◽

10.1201/9781420049398.ch17 ◽

1997 ◽

Cited By ~ 1

Author(s):

James Schepers ◽

Tracy black mer ◽

Dennis Francis

Keyword(s):

Nitrogen Content ◽

Plant Tissue ◽

Chlorophyll Meter

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Study on greenhouse soil nitrogen absorption and soil layer transport of different summer catch crops with different planting density in North China

E3S Web of Conferences ◽

10.1051/e3sconf/202014302023 ◽

2020 ◽

Vol 143 ◽

pp. 02023

Author(s):

Pei Zhiqiang ◽

Lu Shuchang ◽

Wang Xi ◽

Hou Kun ◽

Ya Zongjie ◽

...

Keyword(s):

Nitrogen Content ◽

Soil Nitrogen ◽

Sweet Sorghum ◽

Nitrate Nitrogen ◽

Soil Layer ◽

Reduction Rate ◽

Planting Density ◽

Nitrogen Absorption ◽

Catch Crops ◽

Waxy Corn

In order to improve the utilization rate of nitrogen fertilizer and reduce the environmental pollution risk of the nitrogen accumulation in the vegetable field, this study was carried out in the summer leisure period of the greenhouse vegetable production. This experiment designed different planting density treatments in 2017 and 2018, i.e. for catch waxy corn, 3300 plants/667m2 (WCD1), 5000 plants/667m2 (WCD2), 6600 plants/667m2 (WCD3), for forage sweet sorghum, 4500 plants /667m2 (FSS4), 7000 plants/667m2 (FSS5), 9000 plants/667m2 (FSS6) in 2017; and for catch waxy corn, 4500 plants/667m2 (WCDI), 7000 plants/667m2 (WCDII), 9000 plants/667m2(WCDIII), for forage sweet sorghum, 7000 plants/667m2 (FSSIV), 10000 plants/667m2 (FSSV), 14000 plants/667m2 (FSSVI) in 2018. The results showed that the biomass and nitrogen absorption of the two catch crops began to improve and then decreased with the increase of planting density. The nitrogen absorption amount of the catch waxy corn and forage sweet sorghum was 22.36~28.68 kg/667m2,21.67~24.39 kg/667m2, respectively. Different planting density of catch waxy corn and forage sweet sorghum could significantly reduce the total nitrogen content of 0~30cm soil layer and the nitrate nitrogen content of 0~90cm soil layer, for catch waxy corn and forage sweet sorghum, the reduction rate of total nitrogen content in 0~30cm soil layer was 9.6%~27.0%, 5.7%~23.5%, the reduction rate of nitrate nitrogen content reached 50.0%~90.8%, 80.1%~96.4%, respectively, which effectively controlled the nitrate nitrogen leaching to soil deep layer. Planting catch crops could increase soil urease activity, regulate soil nitrogen transformation. Compared with other treatments, WCDII and FSSV treatment can reduce the initial urease activity and soil nitrate nitrogen content of next crops, which is consistent with the nutrient requirements of broccoli in the early stage of growth. These catch crops planting could reduce the nitrogen environmental risk in the greenhouse soil. Finally, the study proposed that the suitable planting density of catch waxy corn and forage sweet sorghum planted was 6600~7000 plants/667m2, and 9000~10000 plants/667m2, respectively, in the greenhouse summer leisure period. It is more advantageous to improve soil nitrogen absorption and reduce soil nitrogen environmental risks for catch waxy corn.

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Photosynthetic pigments estimate diet quality in forage and feces of elk (Cervus elaphus)

Canadian Journal of Zoology ◽

10.1139/cjz-2014-0154 ◽

2015 ◽

Vol 93 (1) ◽

pp. 51-59 ◽

Cited By ~ 2

Author(s):

D. Christianson ◽

S. Creel

Keyword(s):

Nitrogen Content ◽

Photosynthetic Pigments ◽

Diet Quality ◽

Cervus Elaphus ◽

Linear Models ◽

Energy Content ◽

Photosynthetic Pigment ◽

Neutral Detergent Fiber ◽

Botanical Composition ◽

Fecal Nitrogen

Understanding the nutritional dynamics of herbivores living in highly seasonal landscapes remains a central challenge in foraging ecology with few tools available for describing variation in selection for dormant versus growing vegetation. Here, we tested whether the concentrations of photosynthetic pigments (chlorophylls and carotenoids) in forage and feces of elk (Cervus elaphus L., 1785) were correlated with other commonly used indices of forage quality (digestibility, energy content, neutral detergent fiber (NDF), and nitrogen content) and diet quality (fecal nitrogen, fecal NDF, and botanical composition of the diet). Photosynthetic pigment concentrations were strongly correlated with nitrogen content, gross energy, digestibility, and NDF of elk forages, particularly in spring. Winter and spring variation in fecal pigments and fecal nitrogen was explained with nearly identical linear models estimating the effects of season, sex, and day-of-spring, although models of fecal pigments were consistently a better fit (r2adjusted = 0.379–0.904) and estimated effect sizes more precisely than models of fecal nitrogen (r2adjusted = 0.247–0.773). A positive correlation with forage digestibility, nutrient concentration, and (or) botanical composition of the diet implies fecal photosynthetic pigments may be a sensitive and informative descriptor of diet selection in free-ranging herbivores.

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