J. Benton Jones

Elemental analysis of soil extracts and plant tissue ash by plasma emission spectroscopy

Abstract A method for the analysis of soil extracts and plant tissue ash solutions is described using a direct reading plasma emission spectrometer. The instrument is programed for 16 elements and is capable of determining the elemental content in prepared solutions at a very rapid rate and at sensitivity levels equal to or better than that obtained using the atomic absorption technique.

Hydroponics: Its history and use in plant nutrition studies

Abstract Hydroponics is a widely and frequently used technique for growing plants without soil, providing for a considerable degree of control of the elemental environment surrounding the root. The technique has an interesting history of development and use dating back into the mid 18th‐century, although the growing of plants in nutrient rich water may have dated back into the early history of man. The determination of the essential elements required by plants were discovered using solution culture techniques. This paper discusses the past history of solution culture as well as its importance and use today.

Universal soil extractants: Their composition and use

Universal extraction reagents are defined as a single extractant for use on a range of soils for the determination of both major elements and micronutrients. The first universal extractant, so name...

Soil test methods: Past, present, and future use of soil extractants

Abstract A review of methods for soil extraction used in the United States is given starting from the early 1940s to today. With the use of multielement analyzers, primarily the inductively coupled plasma emission spectrometer (ICP‐AES), extraction procedures being adopted today are those with multielement capabilities, such as Mehlich No. 3 and ammonium bicarbonate‐DTPA (AB‐DTPA).

Nutrient deficiencies and toxicities in plants: nitrogen

Current literature review and discussion of the N status of plants as related to their growth and yield and quality of produced product.

Soil testing in the united states

Abstract There has been a marked change in the soil testing procedures used in the United States by state soil testing laboratories since the early 1950s. In the Coastal Plain states of the south and east, the Double Acid extraction procedure is used for P, K, Ca, and Mg determinations. Bray P1 is the most frequently used method for P extraction except for the alkaline soils of the west where the Olsen method is used. Neutral normal ammonium acetate is the most frequently used extractant for K, Ca, and Mg determinations. The Morgan extraction procedures for P, K, Ca, and Mg, commonly used in the 1950s, is used by only a few states in the northeast and west. Although similar extraction reagents are used in many sections of the United States, there is considerable variance among states regarding weighed versus volume sampling, soil to solution ratio, shaking speed and time, and extraction vessel size and shape. For soil water pH, there is little variance in method as most states are using a 1:1 soil to so...

Analysis of Plant-Ash Solutions by Spark-Emission Spectroscopy

A method for analyzing plant tissue ash by direct-reading emission spectroscopy is described. The procedure developed gives highly reliable results for 16 elements. The method of converting instrument counts to concentration using a computer program is included.

Phosphorus toxicity in tomato plants: when and how does it occur?

Abstract For many years and in most agricultural production systems, phosphorus (P) has been identified as the most frequently occurring essential element deficiency limiting crop yields, and it is still an element that continues to receive considerable research attention. However, little has been researched or written about the effects of high P on plants other than that associated mainly with zinc (Zn) nutrition, and iron (Fe) to some degree, as high P levels are known to interfere with their normal metabolism. Also, P is known to promote manganese (Mn) uptake. At what levels P would be considered toxic has not been clearly defined for most crops. The author has observed the occurrence of nutritional stress in tomato plants when the P level in leaves exceeds 1.00% of its dry matter, mainly occurring for container‐grown plants and those being grown hydroponically. This and other data will be presented that suggests that 1.00% P may indeed be the critical level between sufficiency and toxicity for tomato ...

Effects of various dry ashing temperatures on the determination of 13 nutrient elements in five plant tissues

Abstract Dry ashing five different plant tissues at temperatures from 400 to 700° Cat 4 and 15 hours affected the concentration of Al, B, Cu, Fe, K, and Mn found upon analysis by both emission and atomic absorption spec‐troscopy. The elements Ba, Ca, Mg, Mo, P, Sr, and Zn were not affected by the varying temperatures and times. Dry ashing at 500° C for 4 or 15 hours gave results comparable to the known element concentration or that determined by wet ashing. At temperatures below and above 500° C, volitilization losses and absorption occurred.

Distribution of fifteen elements in corn leaves

Abstract The concentrations of several elements were found to be different among the margin, midrib and blade of a corn leaf. The B, Mn and Si content of the margin was higher than that in the midrib or blade. The N, P, Ca, Mg, Si, Mn, B, Cu, Zn, Al, Sr and Mo content of the midrib was less than that in the blade and margin. Element contents of quarter length sections were different as the ratio of blade to margin or midrib varied. These data demonstrate the need to specifically describe leaf sampling technique and preparatory procedure when sampling corn plants for diagnostic purposes. The author recommends that Chapmans suggested leaf sampling procedure for corn be adopted in order to minimize the influence of margin and midribs on blade analyses.