Evaluation of soils with average potassium content summation for implantation of Musa sp in the municipality of Teotônio Vilela, Alagoas

Soil fertility is one of the crucial factors for agriculture, whose main objective is to increase production. Therefore it is extremely important to know the nutritional requirement of cultivars. Fertility-focused studies are essential for fertilization recommendations in all regions, especially in banana cultivation which is a very demanding plant in fertility. Thus, the present work aimed to evaluate soil fertility, emphasizing the quantification of nutrients necessary to ensure the agricultural productivity of musa sp. The research was developed at laudelino farm, municipality of Teotônio Vilela/Alagoas, between 2019 and 2020, where soil amotragens were performed, randomly collected in the 0-20 cm depth layer, removing 1 kg of soil and sent to the soil laboratory of the Campus of Engineering and Agrarian Sciences (CECA) of the Federal University of Alagoas (UFAL) located in the municipality of Rio Largo-AL, for chemical analysis. The hydrogenic potential (pH), phosphorus (P) and potassium (K+) accessible were analyzed; calcium (Ca+2) and tradable magnesium (Mg+2); saturation by exchangeable aluminum (m%), cation exchange capacity CTC at pH 7.0 (T); base saturation (V%) and; organic matter (OM). As a result of the analysis, the following results were obtained: pH content (5.6); OM (14.1 g/kg) P (5.0 mg/dm³) K (110 mg/dm³), Ca2+ (3.42 cmolc/dm³), Mg2+ (2.53 cmolc/dm³); Al3+ (0.00 cmolc/dm³), H (4.41 cmolc/dm³), and CTC (T) (10.73 cmolc/dm³); m (0.0 %) and V (59 %). Based on the above results, it is suggested the application of 1,103 kg of limestone in order to increase the base saturation to 70%, in addition to the addition of 50 kg/ha of N and 343.5 kg/ha of P2O5 and 96.7 kg/ha of K2O. It is worth mentioning that their applications in the soil must be carried out through sources of 837.8 kg/ha of triple superphosphate; 161.2 kg/ha of potassium chloride and 111 kg/ha of urea. It is also essential to add 30 to 50 t/ha of organic matter, such as bovine manure to the soil, aiming at better utilization of the material by crops.

Alleviating Soil Acidification and Increasing the Organic Carbon Pool by Long-Term Organic Fertilizer on Tobacco Planting Soil

Long term tobacco planting leads to soil acidification. A ten-year experiment with various fertilization treatments (no fertilization (CK), chemical fertilizer (CF), organic-inorganic compound fertilizer (OCF), and organic fertilizer (OF)) was carried out between 2010 and 2020 in a continuous cropping system of Nicotiana tabacum in the brown soil of eastern China, to assess the effects of organic fertilizer on the improvement of tobacco planting soil acidification. The results indicated that treatments OCF and OF reduced the soil exchangeable acid content, of which the exchangeable aluminum showed the largest reduction by 51.28% with the OF treatment. In contrast, treatment CF showed more significant increases in exchangeable aluminum (Al)and Al saturation, and also apparently increased soil NO3−-N, NH4+-N and nitrification potential (NP) than other treatments. Treatments of OCF and OF significantly increased the total amount of exchangeable base (EBC) by 37.19% and 42.00% compared with CF, respectively. Redundancy analysis (RDA) showed that NP, NH4+-N, and NO3−-N were the important factors indicating soil acidification, while EBC and exchangeable K were the significant factors restricting soil acidification. Inevitably, OCF could improve the soil organic carbon pool and labile organic carbon pool. The structural equation model (SEM) showed that OCF treatment increased the soil organic carbon pool mainly by inhibiting soil nitrification and reducing the content of exchangeable Al. In conclusion, both OF and OCF treatments were effective methods to alleviate tobacco planting soil acidification, however OCF had more advantages in improving soil organic carbon pool.

Influence of Physicochemical Properties and Parent Material on Chromium Fractionation in Soils

Chromium is an element that possess several oxidation states and can easily pass from one to another, so its behavior in soils is very complex. For this reason, determining its fate in the environment can be difficult. In this research work we tried to determine which factors affect the chromium fractionation in natural soils, conditioning chromium mobility. We paid special attention to the parent material. For this purpose, extraction experiments were carried out on spiked soils incubated for 50–60 days, using H2O, CaCl2 and diethylenetriaminepentaacetic acid (DTPA). The most efficient extraction rate in all soils was achieved using water, followed by CaCl2 and DTPA. We obtained models with an adjusted R2 of 0.8097, 0.8471 and 0.7509 for the H2O Cr, CaCl2 Cr and DTPA Cr respectively. All models were influenced by the amount of chromium added and the parent material: amphibolite and granite influenced the amount of H2O Cr extracted, and schist affected the other two fractions (CaCl2 and DTPA). Soil texture also played an important role in the chromium extraction, as well as the amounts of exchangeable aluminum and magnesium, and the bioavailable phosphorus. We concluded that it is possible to make relatively accurate predictions of the behavior of the different Cr fractions studied, so that optimized remediation strategies for chromium-contaminated soils can be designed on the basis of a physicochemical soil characterization.

A Research on the Fruitfulness of the Reddish-Yellow Acrisol in Serra da Meruoca, Ceará, Brazil

Agriculture, to be successful, needs soil to have a potential nutrient composition that is relevant to plants. Therefore, it is necessary to identify the conditions for farming through soil analysis. Thus, this manuscript makes it possible to analyze the fruitfulness of two samples of the reddish-yellow acrisol—one with vegetation and the other without it—from Serra da Meruoca, a humid area in the semi-arid region of Ceará. Concerning the material and method, the stages were literature review, researches on cartographic bases, fieldwork, and data collection and their analysis in the laboratory. The results show that the area of acrisol with vegetation favors the practice of agriculture, a fact observed because of carbon (C), which is indicative of soil with intense cultivation, as well as calcium (Ca), which appeared in a significant level, typical of arable land. In the second sample, the acrisol without vegetation, the parameters that impose restrictions on agriculture are the pH, which contains exchangeable aluminum, indicative of high acidity that leads to a leaching process. Also, the aluminum (Al) at a low level reflected the need for dolomitic quicklime, for the amendment of a deficient soil. Therefore, studies on its fruitfulness are essential for farmers to reap the rewards according to the results obtained and analyzed.

Forest Soil Cation Dynamics and Increases in Carbon on the Allegheny Plateau, PA, USA Following a Period of Strongly Declining Acid Deposition

Reductions in exchangeable calcium and magnesium and increase in exchangeable aluminum concentrations have been shown in soils impacted by acid deposition, including at four sites on the Allegheny Plateau, PA, USA, sampled in 1967 and 1997 during a period of peak deposition. We repeated sampling at these sites in 2017 to evaluate changes in soils during the more recent period when there has been a strong decline in acid deposition. The uppermost horizons, including the Oa and A horizons where humified organic matter transitions to mineral soil, were thicker, had higher concentrations of organic carbon and exchangeable calcium and magnesium, and lower concentrations of exchangeable aluminum in 2017 compared to 1997, approximating values measured in 1967. Below the Oa/A horizons, 2017 soil chemistry was more similar to the 1997 results, with some reduction of Ca in the recent measurements. These results suggest recovery of base cation–aluminum balance in surface horizons and may indicate a reduction of aluminum mobilization and increased efficiency of vegetation recycling of nutrients with decreased acid anion concentrations. These changes are consistent with a partial recovery from acid deposition. However, the increase in humified soil organic matter may also be affected by coincident increases in temperature and soil moisture.

Viabilidade técnica do uso de gesso reciclado da construção civil como insumo agrícola

A disposição de resíduos de gesso sem os cuidados necessários promove a contaminação do ar, do solo e do lençol freático. Entretanto, há possibilidade de reciclagem e utilização desses materiais como insumo agrícola, os quais podem promover resultados semelhantes ao gesso agrícola no cultivo de culturas de ciclo curto. Essa pesquisa avaliou a viabilidade técnica e o custo da utilização de gesso reciclado derivado da construção civil como substitutivo ao gesso agrícola, por meio de um experimento onde se observou o seu desempenho a campo na neutralização do alumínio trocável e disponibilização de cálcio mais magnésio no solo. Também se comparou o desenvolvimento e a produtividade da cultura do milho na área experimental, que foi composta por nove tipos de tratamento com quatro repetições distribuídos de forma casualizada em 36 parcelas, totalizando uma área de 241,5m². Após o desenvolvimento completo do milho coletou-se amostras de solo de todos os tratamentos e de indivíduos em todas as parcelas, os quais foram separados e pesados. Os resultados demonstraram que o gesso reciclado, se comportou de forma semelhante ao gesso agrícola ou foi mais eficiente na neutralização do alumínio trocável e na melhoria nos índices de Capacidade de Troca Catiônica. Quanto à produção vegetal, verificamos estatisticamente que não houve diferença significativa entre as parcelas. Conclui-se que o gesso reciclado é um substituto eficiente para o gesso agrícola, mas ainda necessita de uma cadeia de reciclagem e beneficiamento que possibilite sua oferta aos agricultores a um custo menor que a do gesso agrícola. Technical feasibility of using recycled gypsum of civil construction as an agricultural inputA B S T R A C TThe disposal of gypsum waste without observing the necessary precautions can promote the contamination of the air, soil and groundwater. However, there is possibility of recycling of this material as an agricultural input promoting a similar result to the agricultural gypsum in the cultivation of crops of short cycle. The present research evaluated the technical feasibility and the cost of the use of recycled gypsum derived from the civil construction as substitutive to the agricultural gypsum derived from mineral tillage, in an experimental area where was observed the field performance of this material as an input for the exchangeable aluminum neutralization and the availability of calcium plus exchangeable magnesium in the soil. The development and productivity of maize in the experimental area were also compared with nine types of treatments and four replications distributed randomly in 36 plots, which resulted in a total area of 241.5m². After the complete development of the maize cycle, soil samples were collected from all treatments as well as from individuals in all plots that were separated and weighed. The results showed that the gypsum recycled had a similar way to the agricultural gypsum, was more efficient with regard to the neutralization of the exchangeable aluminum and the improvement in the Capacity of Cations Exchange. Regarding plant production, it was verified from statistical treatments that there was no significant difference between plots, but still needs a chain of recycling and processing that enables its offer to farmers at a lower cost than the gypsumKey words: recycled plaster, reuse of inputs and peri-urban agriculture, soil remineralizer.