scholarly journals Management of Soil Acidity and Its Relations With Soybean Productivity in Brazilian Savanna

2021 ◽  
Vol 14 (1) ◽  
pp. 50
Author(s):  
Camila Morais Fonseca ◽  
Veridiana Cardozo Gonçalves Cantão ◽  
Carlos Cesar Evangelista de Menezes ◽  
Simone Cristiane Brand ◽  
Gabriel Elias Soares de Araújo ◽  
...  

The soils of Brazilian Savanna, naturally, present acidity problems, making correction practices fundamental to ensure production. Even with so many years since the introduction of agriculture, some soil correction practices are still misused. Thus, the objective was to evaluate soybean yield and chemical changes in a Red Oxisol in the Brazilian Savanna with the use of limestone, associated or not with gypsum, applied superficially and incorporated by harrow and moldboard plow. The experiment was conducted under field conditions, in Rio Verde-GO, cultivating soybeans in the 2015/2016 and 2016/1017 harvests. The experimental design was in randomized blocks, with four replications, with treatments arranged in a 3 × 3 factorial scheme. The first factor refers to the application of superficial limestone and incorporated by harrow and moldboard plow. The second factor was the presence or absence of limestone and/or gypsum (0 + 0; 0.875 + 0 and 0.875 + 1.75 t ha-1). Plant height, number of pods per plant, productivity, pH, Al, CTC, Ca, Mg and V were evaluated, in soil depths of 0-0.2 and 0.2-0.4 m. In the 2016/2017 harvest, the characteristics of pH, CTC, V and contents of Ca, Mg and Al were influenced by the methods of application of limestone and by its use, associated or not with gypsum. There was an increase in pH on the soil surface with the use of limestone and on the subsurface with the use of limestone and gypsum. The moldboard plow provided increases in the contents of Ca and Mg in the soil in comparison to surface application. The moldboard plow incresed in soybean yield, in the second crop, with and without association of gypsum with limestone.

1989 ◽  
Vol 69 (3) ◽  
pp. 711-714 ◽  
Author(s):  
K. I. N. JENSEN ◽  
E. R. KIMBALL ◽  
J. A. IVANY

The half-life of metribuzin applied to a bare soil surface was calculated to be 3–7 d over four field tests. An artificial cover erected after application or a shallow incorporation increased the half-life of metribuzin approximately 2.5- to 3-fold. Leaching out of the 0- to 5-cm-deep sampling zone could not account for loss of metribuzin. It was concluded that metribuzin persistence may be affected by volatility and/or photodecomposition losses under field conditions, especially shortly after application. Key words: Metribuzin half-life, volatility, photodecomposition, row width


2013 ◽  
Vol 28 (1) ◽  
pp. 92-96 ◽  
Author(s):  
Yanliang Tan ◽  
Detao Xiao

Thoron exhalation rate can be obtained through the combination of the ?accumulation chamber? technique and RAD7. Thoron?s rapid decay causes the intake path and the air flow rate to become important factors in calibration. In field conditions, since the flow rate of the internal pump in RAD7 will change as the voltage of the battery decreases, the big drying tube is more suitable for a long measurement than the small drying tube. We developed the method for recalibration of the thoron concentration reading of RAD7 based on the calibration factor for 222Rn, and obtained the thoron exhalation rate from soil surface near by the Radon Laboratory of the University of South China. This method can be applied to develop and improve instruments for measuring the radon exhalation rate.


2020 ◽  
Vol 14 (1) ◽  
pp. 339-344
Author(s):  
Sabah R. Mohammed ◽  
Ivan D. Eskov ◽  
Elsayed M. Zeitar

Background: Fusarium dry rot disease caused by Fusarium sambucinum Fuckel (F. sambucinum) can infect the potato tubers in the field and during storage. Yield losses by F. sambucinum reach 60%. Traditional methods to control Fusarium dry rot are fungicides application, which led to developing many isolates resistant to these fungicides. Objective: The aim of this study is to evaluate the effect of calcium chloride (CaCl2) and chitosan, alone or in combination, on plant development, tuber yield, and Fusarium dry rot disease incidence under field conditions. Methods: Soil inoculated with F. sambucinum before planting. We treated the seed tubers with CaCl2 (0.5 or 1%), chitosan 0.5%, or both. The foliage was sprayed twice with CaCl2 (0.5 or 1%), 0.1% chitosan, or both. During the vegetation period, growth parameters, such as germination (%), plant height (cm), and branches number per plant, were measured. At harvest, we calculated the total and the marketable number of tubers and tuber yield. In addition, during storage, we assessed the incidence of Fusarium dry rot disease on tubers. Results: Results revealed that combined pre-planting application with 1% CaCl2 and 0.5% chitosan with 2 hours intervals, then spraying foliar with 1% CaCl2 and 0.1% chitosan twice with ten days intervals starting at 40 days after planting resulted in: a) increasing the germination, enhancing the growth parameters such as plant height and branches number per plant; b) enhancing the marketable tuber yield by 75.2 and 97.6% in Sante and Kolobok varieties, respectively; c) reducing Fusarium dry rot disease incidence by 61.9-72.7%. Conclusion: The work highlighted that the combined pre-planting and foliar application of CaCl2 and chitosan might be recommended for potato producers to reduce the incidence of Fusarium dry rot disease and augment yields.


2001 ◽  
Vol 44 (2) ◽  
pp. 185-189 ◽  
Author(s):  
Anderson R. Meda ◽  
Marcelo E. Cassiolato ◽  
Marcos A. Pavan ◽  
Mário Miyazawa

A laboratory experiment was conducted to evaluate the effects of water soluble plant extracts on soil acidity. The plant materials were: black oat, oil seed radish, white and blue lupin, gray and dwarf mucuna, Crotalaria spectabilis and C. breviflora, millet, pigeon pea, star grass, mato grosso grass, coffee leaves, sugar cane leaves, rice straw, and wheat straw. Plant extracts were added on soil surface in a PVC soil column at a rate of 1.0 ml min-1. Both soil and drainage water were analyzed for pH, Ca, Al, and K. Plant extracts applied on the soil surface increased soil pH, exchangeable Ca ex and Kex and decreased Al ex. Oil seed radish, black oat, and blue lupin were the best and millet the worst materials to alleviate soil acidity. Oil seed radish markedly increased Al in the drainage water. Chemical changes were associated with the concentrations of basic cations in the plant extract: the higher the concentration the greater the effects in alleviating soil acidity.


2018 ◽  
Vol 14 (15) ◽  
pp. 46
Author(s):  
Álvaro Lamilla Arana ◽  
Eduardo Colina Navarrete ◽  
Carlos Castro Arteaga ◽  
Danilo Santana Aragone ◽  
Guillermo García Vásquez ◽  
...  

The investigation evaluated the effect of fertilizers potásicos with fosfitos on the yield of grain of hard corn (Zea mays L.), in the Property "Santiago", located in the Km 26 way Babahoyo-San Juan, county of Los Ríos. A rehearsal settled down in the hybrid corn DK-7088, measuring the answer from the corn to the application of fertilizers potasic and fhosphite, to determine the dose with more effect on the production. 19 treatments were proven with Chloride of potassium, Sulfate of potassium and Nitrate of potassium, with fhosphite of Calcium, Magnesium and Potassium, more a witness without applications. The used experimental design was complete Blocks at random in three repetitions, the evaluated variables were subjected to the variancia analysis, and the test was applied from Tukey to 95% of probability. The evaluated parameters were: plant height, days to flowering, longitude and ear diameter and yield for hectare. Found increases in grain yield with three treatments, highlighting the treatment with the application of muriate of potash in conjunction with Calcium phosphide (9451,65 kg ha1 ). The results indicate the possibility of increases of more than 49% in relation to the witness (6339 kg ha1 ) where there was applied the treatments.


Author(s):  
Ygor Henrique Leal

Biological fertilizers promote several benefits to the soil, and one of the ways to evaluate their quality is to determine the edaphic respiration. The present study aimed to evaluate edaphic respiration in bell pepper cultivation under doses and times of application of biological fertilizers. Two experiments were performed with applications of biological fertilizers prepared from manure and enriched organic compost, one using bovine manure (BM) and the other, sheep manure (SM). The experimental design used was in randomized blocks, in a 4 x 3 + 1 factorial scheme, with three replications, referring to the doses of biological fertilizers (100, 200, 300 and 400 dm³ ha-1), application times (0, 30 and 60 days after transplanting – DAT) and the absolute control. The following variables were evaluated during the night and day: soil surface temperature (Tsurf) and 10 cm deep (T10), soil moisture (M) and edaphic respiration (ER). SM provided the highest ER in the two shifts evaluated. The use of 400 and 300 dm³ ha-1 of SM, at times of 0 and 30 DAT, respectively, provided greater edaphic respiration in relation to the absence of manure during the day.


The creation of a selection material for oil flax with a large number of stems, side shoots and an optimal height for cultivation is an urgent task, since the formation of additional bolls on the side shoots will increase the yield of seeds, and an increase in the vegetative mass of plants will increase its competitiveness against weeds and reduce moisture evaporation. from the soil surface. The use of genetic and statistical parameters allows to efficiently plan and carry out breeding work for oil flax, purposefully select parental pairs in crosses, select valuable genotypes, and reject low-value material at the first stages of breeding. The purpose of this study is to identify promising interspecific hybrid combinations based on breeding and genetic parameters for creating a new breeding material for multi-stem and multi-shoot forms. The studies were carried out at the Institute of Oilseeds NAАS of Ukraine in 2018-2020. The material of the research was F1 and F2 hybrids obtained in a system of dialle crosses with the participation of two wild species (L. angustifolium and L. hispanicum) and three samples of cultivated flax – L 6 (India), M 32/2 (Ukraine), L 5 (Czech Republic). The degree of dominance of traits in hybrids of the first generation was determined by the formula (Beil, Atkins 1965). The degree of heterosis is according to the formula (Rasul et al 2002). The coefficient of heritability in hybrids of the second generation – according to the formula (Ayala 1984). As a result of the research, interspecific hybrid combinations have been identified that are promising for obtaining breeding material with a modified habit: – with the effect of heterosis: by plant height – seven combinations of F1 (Ht = 3,58-13,76%); the number of stems per plant – one (Ht = 35,77%); the number of side shoots is six (Ht = 5,68-43,79%). The most valuable are combinations in which the effect of heterosis manifested itself simultaneously on two grounds – the height of the plants and the number of lateral shoots on the plant – L. angustifolium / L 6, L 5 / L. angustifolium, L. hispanicum / L 6, L 6 / L. hispanicum; plant height and number of stems per plant – M 32/2 / L. hispanicum; – with high coefficients of heritability: by plant height – four combinations of F2 (H = 0,67-0,87); the number of stems per plant – six (H = 0,66-0,81); the number of side shoots is four (H = 0,66-0,72). Interspecific combinations of L. hispanicum / M 32/2 and M 32/2 / L. hispanicum were distinguished by high rates of heritability by two characteristics – the number of stems and the number of lateral shoots on the plant. The potential of the selected combinations will be used in the further breeding process for increased branching.


Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 939-943 ◽  
Author(s):  
Ribas A. Vidal ◽  
Thomas T. Bauman

Experiments were conducted from 1992 through 1994 to determine the effect of 0 to 12 Mg ha−1of surface wheat residues (SWR) on giant foxtail density and crown node length, and soybean yield. Giant foxtail density decreased as SWR increased from 0 to 12 Mg ha−1. SWR of 6 to 12 Mg ha−1reduced giant foxtail density by 2 to 50 % compared to bare soil. The crown node of giant foxtail was 2 cm above the soil surface with 12 Mg ha−1of SWR. Frost in 1992 injured soybean more than weeds in plots with SWR while soybean in soil with no SWR was not injured. In absence of frost in 1993 and 1994, yield of weedy soybean increased 20 to 29%, respectively, with the increase of SWR from 0 to 6 Mg ha−1. In weed-free plots, soybean yield was similar across all SWR levels. These results confirm the hypothesis that high levels of SWR increased soybean yield in weedy plots because of decreased giant foxtail infestation.


Weed Science ◽  
1971 ◽  
Vol 19 (1) ◽  
pp. 82-86 ◽  
Author(s):  
G. A. Wicks ◽  
O. C. Burnside ◽  
C. R. Fenster

Downy brome (Bromus tectorumL.) seedling emergence was greatest from soil depths of 1 inch or less, but occasionally seedlings emerged from depths of 4 inches. Downy brome seed covered by soil germinated more rapidly than those seed on the soil surface. More downy brome seedlings emerged, and from greater depths, from coarse-textured soils than fine-textured soils when moisture was not limiting. Soil type did not influence longevity of downy brome seed buried in the soil. Most (98%) 8-month-old downy brome seed buried 8 inches in the soil germinated but did not emerge in 1 year; and none remained viable in the soil after 5 years. The moldboard plow was more effective in reducing downy brome populations than a sweep plow or one-way disk in a continuous winter wheat (Triticum aestivumL.) cropping system.


Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 534-539 ◽  
Author(s):  
John Cardina ◽  
Heather M. Norquay ◽  
Benjamin R. Stinner ◽  
David A. McCartney

Studies were conducted from 1989 to 1993 in continuous no-tillage and moldboard plow corn fields to describe rates of velvetleaf seed predation with time and with seed density, and to identify principal seed predators. Rates of seed loss from the soil surface averaged 1 to 57% day−1and were equivalent in the two tillage systems. Predator populations were the same in no-tillage and moldboard plow fields. The predation rate was generally low in winter months, increased in mid-summer, and declined in late summer. In 2 of the 4 yr, predation increased in October and November. The predation rate was described by an exponential decay function of seed density, with high rates of seed loss at low densities and leveling off to a nearly constant level at densities above 600 seeds m−2. Predation was highest where seed access was not restricted, and exclosures of 6.5 and 1.6 cm2reduced predation up to 15 and 52%, respectively. Mice were important predators in the field. In laboratory feeding studies, the carabid beetleAmara cupreolata, the slugsArion subfuscusandDeroceras reticulatum, and cutworms (Agrotis ipsilon) consumed imbibed velvetleaf seeds.Amara cupreolataand A.subfuscuswere the only predators to damage unimbibed velvetleaf seeds.


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