COMPARATIVE POTASSIUM LEVELS REMOVED FROM SOILS BY ELECTRO-ULTRAFILTRATION AND SOME CHEMICAL EXTRACTANTS

1985 ◽  
Vol 65 (1) ◽  
pp. 25-34 ◽  
Author(s):  
W. VAN LIEROP ◽  
T. SEN TRAN

The objective of this study was to compare extractable potassium levels removed from soils by electro-ultrafiltration (EUF) and by conventional chemical soil tests. Accordingly, concentrations of potassium removed from soils by three EUF and six chemical extraction procedures were compared, on a group of 50 soils which contained less than 20% clay and on a second group of 52 soils which contained from 20 to 50% clay, by means of regression and correlation techniques. The following three EUF extraction procedures were tested: (i) 50 V at 5-min; (ii) 50 V at 5-min plus 200 V at 25-min; and (iii) 300 V at 15-min. Results indicated that the concentrations of soil K found in the combined anolyte and catholyte of the EUF or removed by the chemical procedures were very closely related (r-values generally greater than 0.90). However, EUF was less efficient in removing K from soils containing higher proportions of clay than NH4OAc, the new Mehlich solution, or the double acid mixture used at 1:30 wt/vol soil-solution ratio. As soil K fractions extracted by different EUF procedures were closely related among themselves as well as between the chemical methods tested, EUF would not provide soil fertility information that could not be obtained by less laborious and expensive chemical procedures. Key words: Soil testing, NH4OAc, double acid, new Mehlich extractant, electro-ultrafiltration

1992 ◽  
Vol 72 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Liangxue Liu ◽  
T. E. Bates ◽  
T. S. Tran

The extractions of soil K by electroultrafiltration (EUF) and by chemical methods were compared as predictors of plant-available K for greenhouse-grown alfalfa on 38 Ontario soils. The relation of soil properties to the amount of K extracted by EUF fractions was also examined. The contents of silt and clay were negatively correlated with EUF-K at 50 V and 22 °C and positively correlated with EUF-K at 400 V and 80 °C. Soil pH and organic matter were not significantly correlated with the amounts of K extracted in the EUF-K fractions. The EUF extraction of K was influenced by the presence of carbonate or high exchangeable calcium in soils. Similar correlations were obtained between K uptake and K extracted by chemical methods and the sum of EUF-K fractions. When used along with other soil properties, EUF-K fractions and K extracted by chemical methods predicted availability of soil K with roughly equal ability. The model using the sum of K extracted by EUF at 50, 200 and 400 V is the simplest one and contains three variables, K, K2 and Ca2. The use of EUF is limited due to cost of equipment and time required for analysis, unless a number of nutrients can be accurately determined on one extract. Among the chemical methods, equations developed using three nonacidic extradants, NaCl, ABDTPA and NH4OAc explained more variation in K uptake than two acidic extractants, Mehlich 3 and 0.1 M HNO3. The NaCl model, ABDTPA model and NH4OAc model contained the same variables and had similar R2 values (0.88–0.91). Key words: Available K, chemical methods, electro-ultrafiltration, EUF-K fractions, K uptake


2021 ◽  
Vol 03 (01) ◽  
pp. 72-74
Author(s):  
Nərgiz Musa qızı Nəsirli ◽  

Pollution of the environment with waste is the basis of the degradation of the natural system. To prevent this, it is necessary to protect natural resources as much as possible and organize the recycling of waste. Azerbaijan has sufficient resources to prepare organic fertilizers based on new technologies. The presented article discusses the damage caused to the environment by pollution of lands of Neftchala region. The need for agro-technical measures to restore such areas that have lost their fertility is emphasized. In landscaping research, it is recommended to grow soybeans on such lands and apply high doses of organic fertilizers to ensure their normal development. Key words: soil fertility, corn, nutrients, productivity, quality indicators


2020 ◽  
Vol 54 (9-10) ◽  
pp. 983-991
Author(s):  
MAHESHANI P. A. NANAYAKKARA ◽  
WALAGEDARA G.A. PABASARA ◽  
ADIKARI M.P.B. SAMARASEKARA ◽  
DON A.S. AMARASINGHE ◽  
LALEEN KARUNANAYAKE

As rice is the staple food of most Asian countries, rice straw has become one of the largest agricultural wastes in Asia. It has not been subjected to adequate value additions yet. However, it has excellent potential to be converted to valuable materials, as it contains a significant amount of cellulose. Therefore, it would be beneficial in many ways to identify the cellulose yields of straws of different rice varieties. In general, the cellulose content of biomass is determined by wet chemical methods. Though these methods are accurate, they are not convenient to use under industrial conditions. This research work focuses on investigating the potential of thermal analysis as an alternative way to predict cellulose yields. For the study, rice straws of most frequently cultivated traditional Sri Lankan rice varieties: Suwandel and Raththal, as well as technically modified Sri Lankan rice varieties: BG300 and BG352, were selected. The results obtained by the proposed method were validated by an established three-step chemical extraction process.


Soil Research ◽  
1989 ◽  
Vol 27 (4) ◽  
pp. 699 ◽  
Author(s):  
JD Armour ◽  
GSP Ritchie ◽  
AD Robson

The effect of the incubation of zinc (Zn) applied to the soil on Zn uptake and the Zn concentrations in chemical extractants was studied. In a glasshouse experiment using a Zn-deficient gravelly sandy loam, the effect of recently applied Zn was compared with that of Zn incubated with the soil for 15 days at 40�C on growth and Zn uptake by navy beans (Phaseolus vulgaris cv. Gallaroy). At the second harvest (33 days after sowing), the dry weight of shoots of recently applied Zn was consistently higher than that of incubated Zn, except at the highest rate of 1 �g Zn g-1 soil, where yields were similar. Comparisons of the slope of the linear regressions of Zn uptake as a function of rate of application showed that incubated Zn was approximately 80% as effective as recently applied Zn. A laboratory experiment measured the decrease in Zn concentration in HCl, EDTA, DTPA, and dilute CaCl2 with incubation for up to 8 days at 40�C in four contrasting soils from Western Australia and Queensland. An addition of 2.5 �g Zn g-1 soil increased the concentration of Zn in all extractants at all times of incubation compared with the untreated soil. The recovery of the added Zn was generally highest with HCl and lowest with 0.002 M CaCl2 and decreased exponentially in all extractants with increasing time of incubation in all soils. The order of the rate of decrease in Zn concentration for all extractants was krasnozem > gravelly sandy loam > sand > sandy clay loam. The model, Y = CtB, where C and B are constants, was used to describe the relationship between the recovery of added Zn and time of incubation.


Soil Science ◽  
1949 ◽  
Vol 67 (4) ◽  
pp. 279-286 ◽  
Author(s):  
J. W. WHITE ◽  
F. J. HOLBEN ◽  
C. D. JEFFRIES ◽  
A. C. RICHER

Author(s):  
Arusey Chebet ◽  
Otinga A. Nekesa ◽  
Wilson Ng’etich ◽  
Ruth Njoroge ◽  
Roland W. Scholz ◽  
...  

The objective of this study was to evaluate the effects of site-specific fertilizer recommendations on maize yield using the transdisciplinary (TD) process. 144 farmers participated in the study for the two seasons. Experiments were laid on the farmers’ fields at four sites (Kapyemit, Kipsomba, Ngenyilel and Ziwa, in Uasin Gishu County) using Randomized Complete Block Design in a 3 x 2 factorial arrangement. Treatments included farmers who participated in the TD process (TD2) and those who did not (TD1) in using the interventions for soil fertility improvement which were farmer own practices (ST1); farmers who applied government recommendations (ST2), and site-specific fertilizer recommendations (ST3) which was based on soil testing results. The Data collected was the dry weights of maize which were measured at the end of the seasons and subjected to Analysis of Variance using Genstat 14th edition. Means separation was done using Fischer’s unprotected Least Significant Difference.. There was a significant effect on maize yields by soil testing and participation in TD process p = 0.01. The mean maize grain yield for season one was 5.43 ton ha-1 while for season two was 5.73 ton ha-1. Control farmers (TD1) maize grain yield of 5.27 ton ha-1, had a significant difference (p = 0.05) from the yield of participating farmers (TD2) who had 5.96 ton ha-1. Maize grain yield was increased by the application of site specific fertilizer recommendations which gave an overall mean of 6.57 ton ha-1 for season one and 6.56 ton ha-1 for season two. Following (ST3) recommendations and participation in the TD process, improved soil nutrient content thus maize yield increased. We recommend soil testing and consequent site-specific fertilizer recommendations for any initiative in managing soil fertility.


Soil Research ◽  
1994 ◽  
Vol 32 (2) ◽  
pp. 229 ◽  
Author(s):  
MJ Mclaughlin ◽  
PA Lancaster ◽  
PG Sale ◽  
NC Uren ◽  
KI Peverill

Increasing laboratory costs and time constraints have stimulated development of techniques which allow the simultaneous extraction of many elements from soil. We assessed several techniques using cation/anion exchange resins which allow the simultaneous extraction of Ca, Mg, K, Al, Mn and P from soil. Elements are extracted by shaking soil either with resin beads or resin membranes in distilled water. The resin is separated from the soil and elements are desorbed using BaCl2/HCl. Concentrations of elements in solution are then determined by conventional chemical methods. Using 50 soils which varied in acidity/fertility, a comparison was made between concentrations of elements extracted by the resin methods and commonly used extraction procedures. Apart from Al, concentrations of elements extracted by the resin procedures correlated well with conventional extraction procedures, although P was less well correlated (R2 < 0.8) than cations (R2 > 0.8). All the resin procedures have the potential to reduce the time required for analysis of Ca, Mg, K, Mn and P in soils. The resin membrane method offers considerable speed and cost advantages over the unconfined resin bead method.


2019 ◽  
Vol 7 (2) ◽  
pp. 159-170
Author(s):  
Joachim B. Nachmansohn ◽  
Patricia Imas ◽  
Surinder K. Bansal

Agriculture is the backbone of the Indian economy, in spite of concerned efforts towards industrialization in the last three decades. Therefore, the soil quality and fertility are the major factors in crop production. Declining soil fertility is one of the primary factors that directly affect crop productivity, and fertilizer-use is a key factor in order to keep soil fertility and productivity. A major factor in declining soil fertility is potassium (K) depletion, especially on smallholder farms where fertilization decisions are not based on regular soil testing. Most of the smallholder soybean producers do not have access and investment capacity to soil testing services. Therefore, there is a need to create K fertilizer recommendations based on empirically verified knowledge at India-specific scale. Such large-scale studies, in local filed conditions, are currently lacking. In order to bridge this gap, and generate proven set of directly applicable recommendations, a large-scale plot trial was launched; the Potash for Life (PFL) project. The study evaluated the K response in soybean when fertilizing with potash on K depleted soils in local variable field conditions. The aim was to (1) evaluate the effect and response consistency of K application on soybean yield, (2) to demonstrate to farmers the increased yield and profitability from K-inclusive fertilization regimes for this crop and give recommendations for transient yield increase, and (3) to raise the awareness among smallholder farmers about the importance of K fertilization. A comprehensive experiment was carried out in Madhya Pradesh (M.P.) and Maharashtra. The methodology was straight-forward; two identical plots side by side, with the only difference that one of them was fertilized with additional potash. The results showed a significant yield increase response from the potash application; the average yield increase was 244 kg ha-1 or 26 % in M.P., and 105 kg ha-1 or 36 % in Maharashtra. This entailed an average additional net profit of ₹ 6,681 INR ha-1 and ₹ 2,544 INR ha-1, in M.P. and Maharashtra respectively. It was concluded that the soil status of plant available K is significantly lower than the plant demand for soybean production in the two states, Consequently, K fertilization is necessary in order to improve agricultural practices and optimizing yields. Ultimately, following recommendations given in this study would allow farmers to generate additional profit, which could further allow them to invest in fine-tuning fertilizer practices through the means of soil testing.


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