Open Access Original Research Article

Sources of Potassic Fertilization in Soybean Production under Different Irrigation Blades

Hudson Carvalho Bianchini, Douglas Jose Marques

Journal of Experimental Agriculture International, Page 1-8
DOI: 10.9734/jeai/2019/v37i130254

Aims: The objective of this research was to evaluate the physiological and biometric parameters of the soybean crop in potassic fertilization sources under different irrigation blades. Two potassium sources (ground rock, “phonolite”, with 9% K2O and potassium chloride with 60% K2O) and five irrigation blades (30, 70, 100, 130 and 160% of the recommended blade) were used.

Study Design: The experimental design was in randomized blocks, with ten treatments and four replications, in a 2 x 5 factorial scheme, totaling 40 vessels.

Place and Duration of Study: Sample: Department of Agronomy, UNIFENAS, between March 2018 and November 2018.

Methodology: Soil moisture was determined through tensiometers, using a water potential of -30kPa, considered adequate for the soybean crop. At the end of the crop cycle, the weight of shoot dry matter, weight of 1000 seeds, weight of seeds standardized to 13% moisture, total chlorophyll, chlorophyll a, chlorophyll b and carotenoids, besides nutrient content of the leaf tissue, were evaluated.

Conclusion: KCl favors the accumulation of dry matter, weight of 1000 grains and grain production in the soybean crop in the different irrigation blades. Phonolite increases calcium and magnesium contents in the leaves, independently of the irrigation blade used, also favoring the increase in phosphorus and sulfur contents when soil moisture increases.

Open Access Original Research Article

Soil Fertilization and Texture on Boron Accumulation and Wood Volume in Corymbia citriodora (Hook) K.D. Hill & L.A.S Johnson

Antônio Lelis Pinheiro, Karine Fernandes Caiafa, Daniel Teixeira Pinheiro, Tássia Fernanda Santos Neri Soares, Rodrigo Vieira Leite, Patrícia Ramalho de Barros, Matheus Ferreira França Teixeira

Journal of Experimental Agriculture International, Page 1-8
DOI: 10.9734/jeai/2019/v37i130255

This study aimed to evaluate the effects of soil fertilization and texture on leaf Boron (B) accumulation and its relation with wood volume of Corymbia citriodora Hill & Johnson. The experiment was set in randomized block with four replications, four B fertilization levels (0, 1.1, 2.2 and 4.4 g.plant-1) in two soils types (sandy and clayey). To determine leaf B content, 25 leaves were collected from the median portion of four trees for each treatment. Leaves were dried on oven and B content was determined by the Azomethine-H method using extract obtained by dry digestion. The diameter at breast height and the total height of 25 trees were collected in all treatments and wood volume was calculated. Data were submitted to analysis of variance and the means adjusted to regression equations. The regression coefficients were evaluated by t-test at 1 and 5% probability. It was verified that clay soil produces more wood, compared to sandy soil. There was a gain increase in foliar B as B doses increased in both soil types. Leaf B affected Corymbia citriodora productivity only in clay soil.

Open Access Original Research Article

Soil Management in the Physical Attributes and the Wheat Crop Irrigated Productivity

Pedro Silvério Xavier Pereira, Aloisio Bianchini, Dryelle Sifuentes Pallaoro, Wininton Mendes da Silva, Rodrigo Fernandes Daros, Antônio Renan Berchol da Silva

Journal of Experimental Agriculture International, Page 1-11
DOI: 10.9734/jeai/2019/v37i130256

The objective of this work was the influence of three management systems on the physical attributes and productivity of irrigated wheat, cultivar BRS-254, in the city of Tangará da Serra, MT, Brazil. The experimental design was a randomized block design in split plots, with eight replications, being considered as plots the three systems of soil management: Conventional management (MC) with two gradations (one heavy and one light); minimum management (MM) with light harrowing; and direct seeding (SD). As a subplot: two layers of soil (0 to 10 cm and 10 to 20 cm) and two seasons, being at 42 and 97 days after sowing (DAS) of wheat. The soil physical attributes evaluated were: macro and microporosity, total porosity, soil density and soil resistance to penetration. The yield of wheat crop was also evaluated. For the effects of MC, MM and SD, of the soil layers and DAS in the parameters macroporosity, microporosity and total soil porosity the MC and MM provided higher values ​​of macroporosity and microporosity decrease at 42 DAS. The macroporosity was higher in the layer up to 10 cm and the microporosity in the 20 cm layer at both the 42 and the 97 DAS. The aeration capacity of the soil followed in ascending order in the management systems SD <MC <MM. In SD there was a significant increase in macroporosity from 42 to 97 DAS. Microporosity presented higher value at 97 DAS. Total porosity, as well as macroporosity, presented the highest value at 42 DAS. For the effects on soil density at 42 DAS it was observed that the lowest density value was found in the MM followed by MC. At 97 DAS, the density values ​​practically returned to the initial value before the management intervention. It was verified that the soil density at the end of the crop cycle had an average value around 1.02 kg dm3. At 42 and 97 DAS the lowest soil density value was found in the 0 to 10 cm layer. In the 10 to 20 cm layer at 42 DAS, the SD had the highest soil density value in relation to the treatments studied, but at 97 DAS the SD had the lowest density value. For the effects on soil penetration resistance it was observed that soil resistance to penetration between MM and MC always remained below 2 MPa. The resistance curve showed that the soil rotation was efficient up to 10 cm depth, as they presented values ​​lower than those found for SD, which presented resistance values ​​between 1.5 and 2 MPa. For the effects on yield of irrigated wheat, the use of MM and SD as a way to reduce soil compaction did not contribute to the increase of yield of irrigated wheat. The MC provided higher productivity.

Open Access Original Research Article

Comparative Study of Herbicides for Pre-Emergence Weed Control in Maize (Zea mays L.) in Derived Savanna of Nigeria

O. A. Aluko

Journal of Experimental Agriculture International, Page 1-11
DOI: 10.9734/jeai/2019/v37i130257

Aims: To evaluate and compare the efficiency of candidate herbicides and  increase the latitude of herbicides for pre-emergence weed control in maize.

Study Design: Randomized Complete Block Design, with three replicates was used in the study.

Place and Duration of the Study: Candidate herbicides were obtained Rainbow Nig. Limited for evaluation. The study was carried out between June – September, 2014 and 2015 at Ibadan (0.7.38N; 003.84E) and Ilora (07.81N; 003.82E) research stations of the Institute of Agricultural Research and Training, Obafemi Awolowo University, Ibadan.

Methodology: Weed flora composition was taken with 1sqm quadrat placed randomly before land preparation. Acetochlor 500 g/L, Acetochlor 900 g/L, Metholachlor 720 g and Ametryn 80 WP were applied randomly at three rates of active ingredient (a.i) at maize sowing, while Atrazine (reference), weed-free and weedy check were the control. Agronomic and weed data were taken, analysed and means separated using Duncans Multiple Range Test (DMRT) at p≤ 0.05.

Results: Result showed that weed flora composition before land preparation was dominated by annual weeds {broadleaves (80%) and grass (20%)}. At 6 weeks after sowing (WAS), weed flora composition comprised of 8% spiderwort, 8% sedge, 25% grass weeds and 59% broadleaf weed species. Weed flora dynamics after treatments application might have been influenced by types of herbicides, herbicidal activities and previous cultural practices. Herbicides application resultantly increased plant height (50%) and grain yield (46 - 60%) relative to plant height in weedy check at both locations. These might have accrued from minimal weed interference hence, high weed control efficiency (WCE) recorded in herbicides applied (WCE ≥80%) and significant reduction in cumulative weed dry matter of about 80%.

Conclusion: Herbicides applied significantly reduced weed growth and enhanced maize grain yield. Notwithstanding, investigation of the benefit cost ratio and the environmental impact assessment of herbicides applied are imperative for sustainability of maize production and agro-ecology.

Open Access Original Research Article

Sorghum Intercropped with Piatã Grass in Eucalyptus Sub-forest

Georgio Martins Moreira, Joadil Gonçalves de Abreu, Roberto Giolo de Almeida, Lívia Vieira de Barros, Virgínia Helena de Azevedo, Inácio Martins da Silva Neto, Carlos Eduardo Avelino Cabral, Larah Drielly Santos Herrera, Wender Mateus Peixoto, Dayenne Mariane Herrera

Journal of Experimental Agriculture International, Page 1-9
DOI: 10.9734/jeai/2019/v37i130258

The objective of this study was to evaluate the behavior of forage sorghum when intercropped with piatã grass and cultivated in eucalyptus sub-forest. The experiment was carried out at the Embrapa Gado de Corte, in Campo Grande - MS. The experimental design was a randomized complete block design with three replications. The main treatments were: monoculture (single sorghum); intercropping (simultaneous sowing of sorghum + piatã grass). The secondary treatments were composed by the sampling sites, with five sites equidistant between the rows of eucalyptus trees (CLFI), with full sun as a control (CLI). The percentage of shading was always higher than 30% in the sub-forest, and the overall average of the system with 63% shade, even after 50% thinning of eucalyptus trees. The intercropping with the grass, an interesting fact, did not affect sorghum grain yield, since it validates the potential of forage sorghum for use in intercropping with perennial grasses, with average grain yield of 2,404.63 kg ha-1. Regarding the sampling sites, it was observed a higher yield in the full sun with 3,283 kg ha-1. The weight of 100 grains was higher for sorghum in monoculture. On the other hand, the upper W1000 was observed at sites A and C. The weight of 1000 grains is considered stable, being affected only under conditions of stress during grain formation. The sorghum intercropped with the piatã grass did not influence the harvest index (HI), while in the shaded environment there was an increase in the harvest index in relation to the full sun.