scholarly journals COMPARISON OF IN-FIELD TECHNIQUES FOR MONITORING PLANT AND SOIL NITROGEN STATUS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 571b-571 ◽  
Author(s):  
T.K. Hartz ◽  
R.F. Smith ◽  
W.L. Schrader
Keyword(s):  
Soil Solution ◽  
Nitrogen Nutrition ◽  
Nitrate Concentration ◽  
Nitrate Content ◽  
Nitrogen Status ◽  
Leaf Reflectance ◽  
Nitrogen Levels ◽  
Highly Correlated ◽  
Petiole Sap ◽  
Irrigated Soils

California vegetable growers are adopting drip irrigation at an accelerating pace, which affords the opportunity for more exacting control of nitrogen nutrition. Consequently, the need for quick, accurate, grower-friendly techniques for monitoring nitrogen status in soil and plant material has increased. Three field monitoring techniques were examined in detail: the analysis of soil water samples drawn by soil solution access tubes (SSAT). leaf reflectance as measured by the Minolta SPAD 502 chlorophyll meter, and petiole sap analysis with a Horiba portable nitrate-selective electrode meter. Nitrate concentration in soil solution was highly stratified in drip-irrigated soils, both with regard to location in the field and position with respect to the drip line, making the use of SSAT technology impractical as a tool for routine N fertigation scheduling. Correlation of SSAT nitrate values to any measure of plant N status was poor. Similarly, leaf reflectance correlated poorly with any measure of tissue N in the crops examined. Nitrate content of petiole sap was highly correlated with conventional laboratory analysis of dry petiole tissue over a range of crops and nitrogen levels.

Petiole sap nitrate concentration to assess crop nitrogen status of greenhouse sweet pepper

2021 ◽  
Vol 285 ◽  
pp. 110157
Author(s):  
Alejandra Rodríguez ◽  
M. Teresa Peña-Fleitas ◽  
Francisco M. Padilla ◽  
Marisa Gallardo ◽  
Rodney B. Thompson
Keyword(s):  
Nitrate Concentration ◽  
Sweet Pepper ◽  
Nitrogen Status ◽  
Petiole Sap

scholarly journals Approach to Petiole Sap Nutritional Diagnosis Method by Empirical Model Based on Climatic and Growth Parameters

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 188
Author(s):  
Alfonso Llanderal ◽  
Pedro García-Caparrós ◽  
José Pérez-Alonso ◽  
Juana Isabel Contreras ◽  
María Luz Segura ◽  
...  
Keyword(s):  
Soil Solution ◽  
Nutrient Concentration ◽  
Prediction Models ◽  
Growth Parameters ◽  
Sampling Period ◽  
Tomato Crop ◽  
Area Index ◽  
Empirical Prediction ◽  
Diagnosis Method ◽  
Petiole Sap

The aim of this work is to evaluate the relationship between the nutrient concentration in petiole sap and different agronomic and climatic variables for a tomato crop grown in a greenhouse in Mediterranean conditions. In addition, the persistence of the nutrient concentration in petiole sap was investigated with the aim of determining the sampling period that implies the best trade-off nutritional information. The experiment consisted of the selection of 20 sampling points inside the greenhouse. The samples of petiole, fully expanded leaf, and soil solution samples were collected weekly from 86 to 163 days after transplanting. Chloride, NO3−-N, H2PO4−-P, Na+, K+, Ca2+, and Mg2+ concentrations were determined in petiole sap and soil solution obtained by suction cups. Nitrogen, P, K, Cl, and Na concentrations were also determined in leaf. Finally, the petiole sap nutritional diagnosis method is the highest sensitive nutritional diagnosis method which compares soil solution and nutrient leaf content related to yield, and the statistical analysis performed in this research demonstrates that crop evapotranspiration (ETc), vapor pressure deficit (DPV), and leaf area index (LAI) are considered the most significant variables that allow the development of these empirical prediction models regarding nutrient concentration in petiole sap.

scholarly journals Soil Monitoring Methods to Assess Immediately Available Soil N for Fertigated Sweet Pepper

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2000
Author(s):  
Alejandra Rodríguez ◽  
M. Teresa Peña-Fleitas ◽  
Francisco M. Padilla ◽  
Marisa Gallardo ◽  
Rodney B. Thompson
Keyword(s):  
Soil Solution ◽  
Nitrogen Nutrition ◽  
Sweet Pepper ◽  
Vegetable Production ◽  
Soil N ◽  
Monitoring Methods ◽  
N Application ◽  
Nitrogen Nutrition Index ◽  
Greenhouse Vegetable ◽  
Combined Data

Excessive N application occurs in greenhouse vegetable production. Monitoring methods of immediately available soil N are required. [NO3−] in soil solution, sampled with ceramic cup samplers, and [NO3−] in the 1:2 soil to water (v/v) extract were evaluated. Five increasing [N], from very N deficient (N1) to very N excessive (N5) were applied throughout three fertigated pepper crops by combined fertigation/drip irrigation. The crops were grown in soil in a greenhouse. Soil solution [NO3−] was measured every 1–2 weeks, and extract [NO3−] every 4 weeks. Generally, for treatments N1 and N2, both soil solution and extract [NO3−] were continually close to zero, and increased with applied [N] for treatments N3–5. The relationships of both methods to the nitrogen nutrition index (NNI), an indicator of crop N status, were assessed. Segmented linear analysis gave R2 values of 0.68–0.70 for combined data from entire crops, for both methods. NNI was strongly related to increasing [NO3−] up to 3.1 and 0.9 mmol L−1 in soil solution and extracts, respectively. Thereafter, NNI was constant at 1.04–1.05, with increasing [NO3−]. Suggested sufficiency ranges were derived. Soil solution [NO3−] is effective to monitor immediately available soil N for sweet pepper crops in SE Spain. The extract method is promising.

Leaf nitrogen as a guide for fertilising macadamia

1997 ◽  
Vol 37 (5) ◽  
pp. 599 ◽  
Author(s):  
R. A. Stephenson ◽  
E. C. Gallagher ◽  
V. J. Doogan
Keyword(s):  
Nitrogen Nutrition ◽  
Current Trend ◽  
Leaf Nitrogen ◽  
Nitrogen Status ◽  
Oil Accumulation ◽  
Inflorescence Development ◽  
Experimental Block ◽  
High Yields ◽  
The Relationship ◽  
Low Nitrogen

Summary. Despite the lack of evidence for a critical level of leaf nitrogen in macadamia, fertiliser management has been largely based on tentative standards for high yielding trees. Trees on a lower plane of nitrogen nutrition, however, produced higher yields of good quality nuts. This study was therefore carried out to establish the relationship between yield and nitrogen status of trees. Three rates of nitrogen fertiliser (0.5, 1.5 and 2.5 kg urea/tree . year; 230, 690 and 1150 g nitrogen respectively) were applied to macadamia trees in 1 of 5 application strategies: 1 application in April (floral initiation); 2 applications, one in April and one in June (inflorescence development); 3 applications, April, June and November (rapid nut growth and premature nut drop); 4 applications, April, June, November and January (oil accumulation); and 12 monthly split applications. Multiple applications were all equal in size. The association between high yields and low nitrogen status was confirmed. In some, but not all, years, yield was negatively correlated with leaf nitrogen, accounting for 47 and 59% of the variation in yield of commercially acceptable nuts (>19 mm diameter) in 1991 and 1993, respectively. It is therefore recommended that the standard for leaf nitrogen in macadamia be lowered from 1.4–1.5 to 1.3% under Australian conditions. These results raise concerns at the current trend for leaf nitrogen to be as high as 1.8%. It would be prudent to cease nitrogen applications on at least a small experimental block until leaf nitrogen declined to 1.3% and then maintain this level for at least 3 years and monitor yields.

Investigation of Nitrogen Fertilization of Cotton by Tissue Analysis

1968 ◽  
Vol 4 (4) ◽  
pp. 311-323 ◽  
Author(s):  
H. O. Burhan ◽  
I. A. Babikir
Keyword(s):  
Nitrate Nitrogen ◽  
Nitrogen Nutrition ◽  
Critical Concentration ◽  
Correlation Coefficients ◽  
Early Flowering ◽  
Nitrogen Levels ◽  
Close Relationship ◽  
Final Yield ◽  
Experimental Treatments ◽  
Degree Of Association

SUMMARYThe concentration of nitrate-nitrogen in cotton petioles was directly related to the rate of nitrogen applied and was greatest at the earliest sampling date, decreasing as the season progressed. There was an increase in the degree of association between the level of nitrogen applied and petiole nitrate-nitrogen, and between petiole nitrate-nitrogen and final yield, up to the time of early flowering, when peak correlation coefficients were reached, after which there was a decline. The level of petiole nitrate-nitrogen showed high positive correlations with the rate of nitrogen application as well as with yield. The final yield showed a significant, positive and linear regression on the level of petiole nitrate at the time of early flowering. A close relationship was also shown to exist between a critical concentration, represented by a narrow range of nitrogen levels in the neighbourhood of 2000 parts per million, and final cotton yield. Yield reductions were related to the number of days petiole nitrogen remained below the critical concentration. The use of petiole analysis as a guide in the nitrogen nutrition of cotton, in the evaluation of various experimental treatments and as an aid in interpreting research results, was demonstrated.

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