Plant Tissue Tests Research Articles

Role of Nutrients in Plants, Its Deficiency and Management

Plants like all living beings need energy source. The energy needed by the plants are uptaken in the form of 17 essential elements. Among which Carbon, hydrogen, and oxygen are derived from surrounding. The remaining 14 essential necessary elements are supplied either from rhizosphere and soil organic matter or by important organic or inorganic fertilizers or value added soil amendments. Plants start showing nutrient deficiency when they do not get the necessary nutrients. More nutrient use can also show poor growth because of toxic chemicals in soil. So, required amount of use and the placement of nutrients is necessary. Soil and plant tissue tests have been developed to assess their’ nutrient content. By analysis, plant scientists determined the nutrient need of plant in a given soil. In addition to the levels of available nutrients, soil pH shows its role in nutrient availability and elemental toxicity in soil. In the majority, disease effect in crop plants has been reduced by fertilizer application. This is due to the host plant tolerance or resistance mechanisms involve these nutrients. When the plants were deficient, the application of nutrients significantly reduced disease.

Plant Tissue Testing: How Precise Is My Lab Data?

The carpenter’s adage of “measure twice and cut once” is an important one in most things we do. But how precise is the tape measure capable of providing that information? In plant tissue analysis, we need to have an understanding of what is realistic with regard to the precision provided by laboratories and not attempt to interpret the results to a finer scale than what is actually achieved. Agricultural and environmental laboratories doing plant analysis are capable of great precision. However, some methods have good precision, and others are relatively less precise. Earn 0.5 CEUs in Crop Management by reading the article and taking the quiz at www.certifiedcropadviser.org/education/classroom/classes/981.

Sampling stage and plant part sampled to determine micronutrient sufficiency in field and horticultural crops

Plant tissue testing requires the selection of the appropriate plant part at best stage of growth when it contains higher content of nutrients. The paper discusses the appropriate stage of growth and plant part to sample for a variety of crops. Micronutrient concentrations were consistently higher in leaves than in any other part of the plant. Leaf sheath in cereals and stems in dicots contained the least amount of nutrients. It is recommended that recently matured leaves in cereals and Brassica spp., young leaves in soybeans and potatoes, and entire plant tops at the 10% bloom stage for forage legumes be sampled to determine the micronutrient nutrient status of these crops.

Corn Response to Sulfur Fertilizer in the Red River Valley

The recent incidence and severity of sulfur (S) deficiency due to a decrease in atmospheric S deposition and greater S removal by crops requires reevaluating current S recommendation for corn (Zea mays L.). Ten on‐farm field trials were conducted to evaluate corn response to S additions at sites in the Red River Valley of North Dakota and Minnesota between 2016 and 2017. Sulfur rates of 0, 11, 22, 33, 44 kg S ha–1 as granular (NH4)2SO4 were broadcasted and incorporated prior to corn planting using randomized complete block design with four replications. Plant tissue S concentration and N/S ratios were determined at two corn growth stages (V6 and V12 in 2016, V12 and R1 in 2017) and grain yield was measured at harvest. Plant tissue S did not increase with S fertilizer at V6 and V12 stages in 2016 whereas in 2017, tissue S increased with 11 kg S ha–1 at two sites in the V6 growth stage. Yield was not related to both soil S and plant parameters. Corn yield increased with 11 kg S ha–1 fertilizer rate at two of ten locations. Lack of response at the remaining sites suggests that S from organic matter and mineralization was enough for crop growth and hence applied fertilizer S had no effect on yield.Core Ideas Corn grain yield increased with S fertilizer at two of ten sites. No response to S fertilizer occurred due to dry early growing season. Plant tissue tests were not reliable indicators in predicting response.

A Review of Methods to Improve Nitrogen Use Efficiency in Agriculture

Management of nitrogen (N) is a challenging task and several methods individually and in combination are in use to manage its efficiency. However, nitrogen use efficiency (NUE) has not been improved to a level, only 33%, as predicted by the researchers while developing nitrogen management tools and methods. The primary objective of this review article is to evaluate methods and tools available to manage nitrogen. Several methods, soil testing, plant tissue testing, spectral response, fertilizer placement and timing and vegetative indexes (leaf area index, and NDVI) through drones, handheld sensors, and satellite imagery were reviewed on the subject of user-friendly and effectiveness towards NUE. No single method was found sufficient to counter the nitrogen loss. Some methods were found time consuming and unsynchronized with N uptake behavior of particular crop, for example, plant tissue testing. Use of precision agriculture tools, such as GreenSeeker, Holland Crop Circle, drone, and satellite imagery, were found better compared to conventional methods such as soil testing, but these tools can only be used when the crop is up. Therefore, N management is possible only through inseason N application methods. When 70% of the applied nitrogen is used by the crops within 25–30 days after planting, for example, corn and potatoes, it is required to apply major N rates through inseason approach and some N at planting using soil test reports. In conclusion, this article strongly advocates using two or more methods in combination when managing N.

Soybean Response to Broadcast Application of Boron, Chlorine, Manganese, and Zinc

Core Ideas Application of B, Cl, and Zn increase soybean tissue concentration of each respective nutrient. Addition of B, Cl, Mn, and Zn do not increase soybean grain yield and have a marginal impact on soybean grain quality. Soil tests for B, Cl, and Zn do not predict soybean grain yield response and no relationships exist between trifoliate B, Cl, Mn, and Zn concentration to grain yield or their respective soil tests. It is unlikely that micronutrients are needed to increase soybean grain yield. Efficient use of micronutrients can potentially increase soybean [Glycine max (L.) Merr.] grain yield and economic return. The objectives of this study were to determine the effect of broadcast application of micronutrients on soybean tissue nutrient concentration and grain yield and the relationships between soil and plant tissue tests. Three separate research trials were conducted at 35 sites from 2011 to 2014. Soybean response to Zn application was evaluated in Study 1; B, Mn, and Zn in Study 2; and B, Cl, Mn, and Zn in Study 3. Fertilizers were broadcast applied to the soil surface and incorporated prior to planting. Application of B, Cl, and Zn increased soybean trifoliate concentration of each respective nutrient but application of Mn did not. Addition of B, Cl, Mn, and Zn did not increase soybean grain yield and had a marginal impact on soybean grain quality. Application of 2.2 kg B ha−1 sometimes reduced soybean grain yield. Soil tests for B, Cl, and Zn did not predict soybean grain yield response and there were no relationships between trifoliate B, Cl, Mn, and Zn concentration to grain yield or their respective soil tests. Increased soybean grain yield did increase the removal of micronutrients, but it is unlikely that micronutrients are needed to increase soybean grain yield. Results from these studies conducted across Minnesota showed that broadcast application of B, Cl, Mn, and Zn do not increase soybean yield except for low Mn (<20 mg kg−1) where Mn application could increase soybean yield.

Adoption of nitrogen-efficient technologies by u.s. Corn farmers.

Anthropogenically introduced nitrogen (N) has compromised environmental quality, but it is an essential element for crop production, particularly corn production. Increasing N use efficiency by adopting eco-innovations such as N soil testing, plant tissue testing, and N transformation inhibitors can ameliorate this problem. Data from the 2010 USDA Agricultural Resource Management Survey of corn producers was used to examine the factors affecting adoption of these practices. Twenty-one percent of the 1840 corn farmers had adopted N soil testing, 3% had adopted plant tissue testing, and 10% had adopted N inhibitors. A multivariate probit regression found significant results for each category of explanatory variable that was examined. Among the findings was the importance of information source for N recommendations. Farmers who did not obtain external recommendations were less likely to adopt all three practices than farmers who received recommendations from a crop consultant. Those who received recommendations from fertilizer dealers were less likely to adopt N soil testing and plant tissue testing. All regions were more likely to adopt N soil testing than the Midwest, and warmer regions were less likely to adopt B transformation inhibitors. Those who adopted conservation tillage were more likely to adopt plant tissue testing and N inhibitors, and those who received conservation payments were more likely to adopt N soil testing and plant tissue testing. Adoption of conservation tillage was also associated with the adoption of several other technologies. Implications for research and educational programs are discussed.

Soil and Plant Tissue Testing

Soil testing is the best tool for monitoring soil fertility levels and providing baseline information for cost-effective fertilization programs. But a major limitation is that it typically accounts for the plant-available nutrient pool present in the surface soil layer. Because of the extensive root system in some plants, plant analysis is a complement to the soil test to better assess the overall nutrient status of a perennial forage system, while revealing imbalances among nutrients that may affect crop production. This 4-page fact sheet was written by Maria L. Silveira and published by the UF Department of Soil and Water Science, June 2014.
 SL412/SS625: Soil and Plant Tissue Testing (ufl.edu)

Response of hydroponically grown head lettuce on residual monomer from polyacrylamide

The aim was to assess acrylamide monomer (AMD) uptake by hydroponically grown lettuce. Lettuce was cultivated by applying plant tissue testing in a recycled system by the use of nutrient solutions prepared with two water-soluble flocculants F3 and F4 containing 176 and 763 mg kg−1 of AMD, respectively. The effects on growth, fresh weight and plant leaf quality were evaluated by comparing these treatments and one control standard nutrient solution typically recommended for lettuce hydroponic cultivation. To assess the nutritional status of lettuce, samples were collected and lyophilised before determination of the selected micro- and macro-element contents. An HPLC with photodiode array detector method was applied to determine AMD in both selected flocculants and dried plant samples. Results show that lettuces cultivated under the conditions described above absorb AMD from nutrient solutions into their leaves. The AMD presence in recycled nutrient solutions has a negative influence on the growth of lettuce, reducing their average fresh weight and average number of leaves. The study confirmed that the problem of AMD mobility and its accumulation risk in plants should to be an important topic with respect to safe polyacrylamide (PAM) handling in the agro food area.

Nitrogen Cycling and Management for Romaine and Crisphead Lettuce Grown on Organic Soils

Lettuce has rapid growth and reaches harvest in 60–70 days in South Florida. This leads to high demands for nitrogen fertilization during the short growing season. A good N fertilization scheme should reduce costs, conserve natural resources, and minimize negative environmental impacts. The keys to using fertilizer efficiently are understanding the crop nutrient requirements to predict fertilizer needs and management as well as knowing the appropriate amounts to apply. Lettuce growers also need to know the nutritional status of the crop through soil and plant tissue testing. This 4-page fact sheet was written by Luis Santos, Alan L. Wright, Yigang Luo, Huangjun Lu, and D. Calvin Odero, and published by the UF Department of Soil and Water Science, September 2013.
 http://edis.ifas.ufl.edu/ss588

Soybean Response to Sulfur Fertilizer Applied as a Broadcast or Starter Using Replicated Strip Trials

Sulfur fertilizer is not recommended for soybean [Glycine max (L.) Merr.] production in the northern Corn Belt even though responses to S have been occurring more frequently in other crops. The objectives of this study were to determine the impact of fluid fertilizer combinations containing N, P, and S on early S uptake, soybean grain yield, and S removal and to evaluate various soil and plant tissue testing factors for predicting S need. Field trials were conducted at four locations, one with a sandy soil and three locations with finer soil textures. Preplant broadcast S was compared with liquid starter N and NP combinations applied with and without S 5 cm beside and below the seed row. Nitrogen increased soybean early plant mass while S increased plant S concentration, uptake, S removal in grain, and grain protein concentration but decreased seed oil concentration. Soybean grain yield was increased by S at one location and was not increased by N or P. Grain yield response to S occurred only when soil organic matter concentration was<20 g kg–1. The factor best correlated to yield response to S was grain S concentration, followed by tissue S concentration at the R2 growth stage and whole‐plant S concentration at the V5 stage. Extractable SO4–S in the soil was negatively correlated to yield response to S. The data indicate that soybean plants will accumulate S in higher quantities than needed for growth and development and that yield response is possible under limited circumstances.

Plant Tissue Analysis and Interpretation for Vegetable Crops in Florida

This guide is provided to assist vegetable growers, UF/IFAS Extension personnel, and consultants in conducting a meaningful plant tissue testing program. Guidelines are provided for collecting samples, proper handling of the sample, and choosing an analytical lab. Information is also presented on basic plant nutrition so that the reader understands the nutrient requirements of each vegetable crop and the process of identifying nutrient deficiencies. The final section of the guide presents the deficiency, sufficiency, and toxicity ranges for plant nutrient concentrations. This is the interpretation portion. Values presented in the tables have been drawn from research from many areas of the country with emphasis on research conducted in Florida. Missing values in the tables indicate areas of research need. The final section of the guide also presents recommendations for nutrient deficiency correction. Originally published January 1991 and revised February 2004. This revision October 2012

Wine Grape Tissue Nutrient Concentrations in the Inland Pacific Northwest

Soil and plant tissue testing is routinely used by growers to assess the status of their crops to determine what, if any, supplemental fertilizers are needed to reach both quality and quantity production goals. In wine grape (Vitis vinifera L.) production, leaf tissue testing is often used as the primary assessment tool for in-season fertilizer adjustment. In this project, we conducted a 3-year survey to evaluate actual leaf nutrient concentrations for comparison with published tissue nutrient guidelines. Leaf petiole and blade samples were collected from six different wine grape cultivars (two white, four red) from eight different sites that geographically encompass Washington's Columbia Valley American Viticultural Area (AVA) (inclusively), the Milton–Freewater area in Oregon, and the Parma area in Idaho. These are all low-rainfall areas (<450 mm/year) in the Pacific Northwest (PNW). Leaf samples (petioles and blades) were collected at bloom and veraison and analyzed for nutrients by a commercial laboratory. Concurrently, replicated nitrogen (N) rate trials were conducted on two Riesling and two Merlot vineyards in the Columbia Valley AVA. The same tissue-sampling technique was employed on grapevines receiving from 0 to 67 kg ha–1 N for up to 4 consecutive years. Results from the vineyard survey and from the N-rate trials show that many of the nutrient concentrations in the sampled tissues fall outside of the ranges currently considered normal or adequate in published standards. However, grapes from the survey and trial sites were all of sufficiently high quality for production of premium wines. This suggests that currently published standards are not appropriate for use in regulated deficit-irrigated wine grapes in the low rainfall areas of the inland PNW.

Using Remote Sensing to Assess the In‐Season Nitrogen Status of Perennial Ryegrass for Seed Production

Currently, perennial ryegrass (Lolium perenne L.) growers in western Oregon rely on yield goal estimates and experience to formulate N rates. This practice may result in insufficient or excessive N fertilizer rates in any given year. Plant tissue testing to determine the in‐season plant N status may improve N management. However, tissue testing can be costly, time consuming, and difficult for growers to adopt. A possible solution to these problems is remote sensing. The objectives of this study were to determine (i) the critical whole‐plant N concentration and N uptake values for perennial ryegrass, (ii) and if remote sensing in the form of aerial images could be used to assess the in‐season plant N status of perennial ryegrass. Research was conducted at four sites in 2007, 2008, and 2009. Analysis found a critical whole‐plant N concentration value of 28.0 g kg−1 and a critical N uptake value of 157.9 kg N ha−1 A significant and strong linear plateau relationship was found between relative near infrared (NIR) and both whole‐plant N concentration (r2 = 0.46) across site‐years. Additionally, a significant and strong linear plateau relationship was found between the normalized difference vegetation index (NDVI) and N uptake (r2 = 0.61) across site‐years. Critical values obtained from these linear plateau relationships were similar to those found through tissue testing, indicating that relative NIR or NDVI may be used as an indirect measurement of whole‐plant N concentration or N uptake in perennial ryegrass grown for seed.

Diagnostic Nutrient Testing

Recommendations made for nutrient applications have traditionally focused on economic yield and quality. However, present-day testing procedures and recommendations are required to simultaneously ensure economical and environmental sustainability of agricultural production systems. A soil test is a calibrated index relating crop response to applied nutrients. Any application rate devoid of an economical response in yield or quality is deemed unnecessary. Therefore, a soil test becomes the first step in any nutrient best management practice (BMP) development, implementation, and monitoring activity. Certain significant areas in Florida, such as calcareous soils, require development of calibrated soil tests rather urgently. Nutrient sufficiency of perennial crops and deficiency diagnostics can be gauged through in-season plant tissue testing. Nutrient delivery for correcting the deficiency through foliar sprays is not always effective, and may require multiple applications. Spectral reflectance methods show significant promise as an alternative to traditional wet chemistry analyses with regard to ease, costs, and speed with wider range of applications, including natural resources. Additional research is needed to develop this technology for field-scale applications. Current research is focusing on environmental nutrient management to include nutrient sources, application rates and timing, nutrient uptake efficiency, retention capacity of soils, estimating and minimizing nutrient losses to the environment, etc. Nutrient loss assessments tools such as the Florida phosphorus (P) index and bahia (Paspalum notatum) and citrus (Citrus spp.) tests for P are now being made possible in Florida through integration of soil and tissue testing methods. Development and improvements of such analytical methods and tools specific to Florida to include other nutrients, heavy metals, soil capacity, and ecosensitive regions, is vital to ensure sustainability to the state's tourism, agriculture, and urban-rural balance.

Foliar Fertilization of Crop Plants

ABSTRACT Essential plant nutrients are mainly applied to soil and plant foliage for achieving maximum economic yields. Soil application method is more common and most effective for nutrients, which required in higher amounts. However, under certain circumstances, foliar fertilization is more economic and effective. Foliar symptoms, soil and plant tissue tests, and crop growth responses are principal nutrient disorder diagnostic techniques. Soil applications of fertilizers are mainly done on the basis of soil tests, whereas foliar nutrient applications are mainly done on the basis of visual foliar symptoms or plant tissue tests. Hence, correct diagnosis of nutrient deficiency is fundamental for successful foliar fertilization. In addition, there are some more requirements for successful foliar fertilization. Foliar fertilization requires higher leaf area index for absorbing applied nutrient solution in sufficient amount, it may be necessary to have more than one application depending on severity of nutrient deficiency. Nutrient concentration and day temperature should be optimal to avoid leaf burning and fertilizer source should be soluble in water to be more effective. Foliar fertilization of crops can complement soil fertilization. If foliar fertilization is mixed with postemergence herbicides, insecticides, or fungicides, the probability of yield response could be increased and cost of application can be reduced.

A Comparison of Liquid Phosphoric Acid and Dry Phosphorus Fertilizer Sources for Irrigated Alfalfa Production on Calcareous Soils

Alfalfa production in the Western United States requires large quantities of phosphorus (P) fertilizer. In 1998, phosphoric acid (PA) became available as a fertilizer source. Phosphoric acid was more expensive per kg of P than other fertilizers, but was promoted on the basis of convenience of application when tank mixed with other chemicals, and superior agronomic performance (higher yield per kg P applied) in alkaline soils due to the neutralizing effect of the acid. The objective of this study was to compare the effects of PA, triple superphosphate (TSP, 0-45-0), and monoammonium phosphate (MAP, 11-52-0) on alfalfa yield and soil and plant tissue nutrient levels. Phosphorus was broadcast at rates based on soil test recommendations for two years at two sites having calcareous soils typical of alfalfa production systems in the Western U.S. At one site, potassium chloride (KCl, 0-0-60) and zinc sulfate were also mixed with the PA based on soil test recommendations. Responses to fertilizer ranged from less than 1 Mg/ha (7 to 10%) to above 6 Mg/ha (44 to 62%) relative to the control. Yield and soil test P were not significantly different among fertilizer sources in either year or location. At one location where more intensive soil and plant tissue testing was done, there were no differences among fertilizer sources in soil or tissue test K or micronutrient concentrations. These results indicate that PA does not have an agronomic (yield) benefit relative to traditional dry P fertilizers for alfalfa produced on calcareous soils. Therefore, the higher cost per kg of P with PA would have to be justified by considerations other than agronomic performance.

Quantitative Approaches for Using Color Infrared Photography for Assessing In‐Season Nitrogen Status in Winter Wheat

Due to the timing and rates of N applications in wheat (Triticum aestivum L.), the potential exists for high N loading to the environment. Plant tissue tests offer growers the ability to determine in‐season N status, and to optimize N applications and N use efficiency. However, sampling and N analysis can be costly, difficult, and time consuming. Remote sensing may offer a solution to these problems. The objectives of this study were to determine (i) if remote sensing could be used to estimate in‐season N status, (ii) if within‐field calibration would improve the ability of remote sensing to estimate crop N status, and (iii) if optimum N rates could be estimated using remote sensing. Research was conducted in 1999 to 2001 at eight sites. Two sites had randomized complete block designs with variety, seeding rate, and N rate as treatments. Six sites had a single seeding rate and wheat variety. Biomass was found to influence spectral measurements of in‐season N status. A strong relationship between the normalized difference vegetation index (NDVI) and growth stage (GS)‐30 whole‐plant N concentration (R2 = 0.69) and GS‐30 N uptake (R2 = 0.61) was found. Within‐field calibration did not improve the estimation of in‐season N status by NDVI. While it was possible to use NDVI to estimate GS‐30 N uptake, predicted N fertilizer rates based on N uptake were highly unreliable. However, NDVI reliably predicted GS‐30 N fertilizer rates based on whole‐plant N concentration for wheat that had mean GS‐30 biomass values &gt;1000 kg ha−1

Empirical Models for Predicting the Dry Matter Yield of Grass Silage Swards Using Plant Tissue Analyses

Quantifying spatial variability in forage grass yield within individual fields is hampered by the lack of accurate yield monitoring equipment. Here, it is shown how dry matter (DM) yield of silage swards can be predicted on the basis of their mineral composition. This empirical method of predicting yield enables diagnoses of sward nutrient status to be made simultaneously from the tissue test information, and provides a unique opportunity for identifying the nutritional and non-nutritional factors responsible for variability in sward productivity at sub-field scales. Maps of sward DM yield at first, second and third cut silage stages in 1999, and at first cut silage stage in 2000, on a large (7.9 ha) grassland field were produced using two different yield models: one model for first cut and a separate model for second and third cuts. The maps indicated that DM production varied considerably across the field, particularly at first cut, but that the pattern of yield variability at this cut was consistent from 1999 to 2000. The results of the plant tissue tests suggested that N deficiency had been responsible for limiting DM production on the lower yielding parts of the field.

Using Nutrient Uptake Patterns to Develop Efficient Nitrogen Management Strategies for Vegetables

Nitrogen (N) in a soil that is not immediately taken up by a crop is subject to leaching, denitrification and other mechanisms of loss. Nitrogen uptake studies identify the total amount of N accumulated by the crop and the period of peak demand. This information can be used to devise management strategies aimed at supplying N preceding anticipated uptake. Split sidedress application, fertigation, and use of controlled release fertilizers (CRN) are all viable options for N management, depending on the crop production scenario and available infrastructure. Soil and plant tissue testing can be useful feedback tools for adjusting N applications for soil contributions of N and unexpected N losses. Efficient irrigation is of paramount importance in achieving efficient N fertilization regardless of management practice.