Behavior of nitrogen in the media supplied with the aqueous phase produced by methane fermentation as liquid fertilizer

pp. 859–864

Behavior of nitrogen in the media was investigated when the aqueous phase produced by methane fermentation was supplied as liquid fertilizer.

When the aqueous phase was supplied to masa-soil,  included in masa-soil was nitrified to . Additionally, in masa-soil,  absorption was observed. On the other hand, in the case of coconut fiber and rockwool, has been hardly nitrified. From above results, it was determined that  toxic effect from the aqueous phase on tomato plants growth was inhibited by means of the progress of nitrification and  absorption by masa-soil.

However, nitrification was restrained so that  was fixed in masa-soil. On the other hand, in the sampled field soil,  was not fixed, and was nitrified immediately. In the field soil, there was a great deal of generated . In comparison with masa-soil.     

Determination of Rhizobitoxine and Dihydrorhizobitoxine in Soybean Plants by Amino Acid Analyzer

Investigations were carried out on the effect of the activity ratio of potassium to calcium and magnesium in the nutrient solution applied by drip irrigation on the growth and nutrient uptake of lettuce (Lactuca sativa var. Great Lakes 366) grown on Tottori sand dune soil.

The of the soil solution was influenced by that of the nutrient solution. Calcium nutrition of lettuce was not influenced by the in the soil solution. However, the magnesium nutrition was improved at a low activity ratio, which resulted in the alleviation of the physiological injury.     

Characterization of zinc adsorption sites in two mineral soils

The adsorption of Zn, as compared with Mg, on two mineral soils, which differed in their major cation-exchange materials and with and without Ca-saturation, was measured in the presence of free CaCl₂.

The adsorption of Zn as well as Mg occurred on cation-exchange sites. The Zn adsorption data conformed to a two-term Langmuir equation. The presence of two kinds of adsorption sites and their numbers and bonding energies were deduced. However, the Langmuir approach was not adopted on the basis of comparison between the total number of the adsorption sites for Zn deduced and the CEC of the soils.

As an alternative approach, the selectivity coefficient as defined by the equation:

was calculated for each adsorption equilibrium and plotted against the amount of Zn adsorbed. This [Zn]_soil plot was used to estimate the capacities of the soil to adsorb Zn with specified affinities. The value varied between 1 and 1,000, whereas the corresponding value varied only between 0.5 and 1. The value was dependent upon the amount of Zn adsorbed, the status of exchangeable cations, and the major cation-exchange materials (montmorillonite VS. allophane-imogolite) in the soils. The importance of surface OH groups in allophane-imogolite as specific adsorption sites for Zn was suggested.     

EFFECTS OF NITROGEN FORMS ON THE GROWTH AND POLYAMINE CONTENTS IN DEVELOPING SEEDS OF VEGETABLE SOYBEAN

A pot culture experiment of nitrogen forms [nitrate (NO^? ₃ ): ammonium (NH ⁺ ₄ )] with four ratios (100:0, 75:25, 50:50, and 25:75) in nutrient solutions was conducted to examine the effect of nitrogen forms on the growth and polyamine contents of developing seeds of vegetable soybean [Glycine max (L.) Merr. cv. ‘Li-xiang 95-1′]. Results showed that the best plant growth vigor was observed in (75%), and then in (50%). However, the fresh and dry weight of biomass decreased when a high concentration of either (100%) or (75%) was the primary nitrogen source in the nutrient solution. The numbers of flowers and pods in (75%) were significantly decreased compared with other ammonium-nitrate ratios in which the numbers of flowers and pods were not influenced by nitrogen forms. During the development of seeds, levels of free Put and Spd decreased, and the decrease extents were more marked in 100:0 and 25:75 (:), but the change of free Spm was opposite. Levels of conjugated and bound polyamines in all nitrogen forms increased, but the increases in 75:25 and 50:50 (:) were not so obvious as in 100:0 and 25:75 (:) treatments. The possible roles of polyamines in the adaptive mechanism of vegetable soybean seeds to different nitrogen forms were discussed.     

Studies on a volcanic ash soil at Ohnobaru,Tarumizu City,Kagoshima prefecture

A volcanic ash soil consisting of more than 40 layers, of volcanic fallout was studied from the standpoint of humus chemistry. According to soil texture and humic acid type, the soil profile was divided into 3 sections as follows: (1) Upper layers formed since 1779 A.D. Loamy sand. Po or A type. (2) Middle layers formed from 1779 A.D. to 5,540 yr. B.P. Sandy loam, A, A or P type. (3) Lower layers formed from 5,540 yr. B.P. to about 20,000 D.P. Sandy clay, loam or clay loam, A± type. The PQ values in the middle layers were lower than those of the upper and lower layers.

The distribution of carbon and nitrogen contents in the fulvic and humic acid and humin fractions of each layer varied considerably. The CfN ratio of the total humus of each layer tended to increase with the increase in its carbon content. C/N ratios of humic acids in the lower layers were higher than those in the upper and middle layers. C/N ratios of fulvic acid fractions were nearly constant (10-13), for all layers examined, and those of humin fractions ranged from 15 to 20, with one exception of 34.

The amounts of sugars, uronic acids and amino acids in hydrolysates of fulvic acids were more or less same for all samples, and sum of the amounts of carbon in these compounds comprised 30 to 40 percent of fulvic acid carbon. Amino acid nitrogen comprised 72 to 94 percent of fulvic acid nitrogen. Seven amino acids were detected, among which aspartic acid, glutamic acid and glycine were predominant.     

Phosphite (phosphorous acid): Fungicide,fertilizer or bio-stimulator?

Abstract

Phosphite (; Phi), a reduced form of phosphate (; Pi), is widely marketed as either a fungicide or fertilizer or sometimes as a biostimulant. This is confusing for both distributors and growers. The present paper explores data from various studies to clarify that Phi does not provide plant P nutrition and thus cannot complement or substitute Pi at any rate. In addition, Phi itself does not have any beneficial effect on the growth of healthy plants, regardless of whether it is applied alone or in combination with Pi at different ratios or different rates. The effect of Phi on plants is not consistent, but is strongly dependent on the Pi status of the plants. In most cases, the deleterious effect of Phi is evident in Pi-starved, but not Pi-sufficient, plants. Plants fertilized with Pi allowing for approximately 80–90% of its maximum growth might still be at risk of the effect. This negative effect becomes more pronounced under more seriously Pi-deficient conditions. Although a number of studies have shown positive crop responses to Phi, these responses are likely to be attributable to the suppression of plant diseases by Phi and/or to Pi formed from oxidation of Phi by microbes. In addition, indirectly providing P by Phi-to-Pi oxidation is not an effective means of supplying P to plants compared with Pi fertilizer. An understanding of these issues will aid the right selection of fertilizer as well as minimize the harmful effects of Phi use on crops.