Corn Production for Silage Subjected to Potassium Fertilization and Water Depths

This study was carried out with the objective of evaluating the effect of water depths and potassium fertilizer levels on corn yield for silage. The experimental design was a randomized block design in a split-plot with six water depths based on crop potential evapotranspiration (ETcp) in levels: 0.25;0.50;0.75;1.00;1.25 and 1.50 ETcp, and six amounts of potassium, 0, 20, 40, 60, 80 and 100 kg·ha-1, in four replicates. The irrigation system was dripped. Before sowing was applied to the soil to nitrogen (N) and phosphate (P) fertilizers, corn was sown ten days after the fertilization using seeds from hybrid AG 1051. Manual harvesting of ears occurred 67 days after sowing. Production variables observed were fresh matter of plant with (FPMwiths) and without (FPMwithouts) the ears. The fresh matter of plant with and without the ears was influenced significantly by factors analyzed, the 1% level of probability by F test. The water depths in irrigation that maximized the physiological parameters of plants as FPMwiths and FPMwithouts were, respectively, 690 mm and 766.7 mm. The quantitative potassium to maximize physiological parameters of FMP with ears and FMP without ears was, respectively, 104.75 kg ha-1 and 52.1 kg ha-1.

Drip irrigated sunflower intercropping

One of the difficulties in the implementation of agroenergy’s cropping is the growing area competition with subsistence crops. Few studies have been conducted to show the efficiency of intercropping between plants of energy’s potential with cultures of economic sustainability. The objective of this study was to evaluate the effectiveness of intercropping sunflower cultivars with corn and beans, in the initial growth under localized irrigation. The experiment was conducted at the end of the year 2012, in an area of 950 m2, located in the Campus II-UEPB, Lagoa Seca, Paraíba. The irrigation system was managed based on the Reference Evapotranspiration (ETo), calculated by the Penmann-Monteith Method with data obtained locally. The experimental design was a randomized blocks factorial (2 × 4) × 3, with treatments combining two varieties of sunflower in four plantation systems: single or isolated, intercropped with maize, with bean and with caupi. Each plot consisted of four rows of sunflowers in spacing 0.3 × 0.7 m and length of 5 m, interspersed with rows of beans or corn, except in the isolated system. The central rows of sunflowers were used to measure the following growth characteristics: plant height, stem diameter, number of leaves and leaf área. Data were subjected to analysis of variance by F test and the means compared by Tukey test at 5% probability. The diversification of sunflower varieties promoted differences in initial growth, regardless of the cropping system. There was significant effect at 15 DAS, where the sunflower variety “Advanta CF101” had higher plants than the variety “Hélio 253” at 40 DAS;the variety “Hélio 253” had a stem diameter greater than the “Advanta CF101”.

Macronutrients Omission in the Growth of Cotton, BRS Topázio Cultivar Grown in Nutritious Solution

With the objective to determine the probable causes of the appearance of abnormalities in BRS Topázio cotton plants, a greenhouse experiment was carried out per subtraction, in which nutrients were omitted: N, P, K, Ca, Mg and S, totalizing 21 experimental units. The omission of N, P, K and Ca in the nutrient solution reduced the biometric characteristics of the cotton crop, with K and Ca being the most affected by these characteristics. The visual symptoms in cotton plants are seen with more severity in the lack of K, P, K Ca and Mg elements. The omission of S did not affect the development of the plants.

Effect of Mineral Fertilization and Irrigation on Sunflower Yields

Among the cultures used for the production of biofuels, the sunflower is one of the most important. Although some information exists, the water and nutritional needs of sunflower in the north east of Brazil are not well known. To fill knowledge gaps, an experiment was carried out to evaluate the effect of nitrogen (N), phosphorus (P), potassium (K) fertilization and available soil water (ASW) on sunflower yields. The sunflower cultivar Embrapa 122-V2000 was subjected to 44 treatments on a completely randomized design generated by the Baconian Matrix with four rates of N (0, 60, 80 and 100 kg&middotha-1), four rates of P2O5 (0, 80, 100 and 120 kg&middotha-1), four rates of K2O (0, 80, 100 and 120 kg&middotha-1), and four available soil water (ASW) levels (55%, 70%, 85% and 100%) replicated three times. Urea was used as a source of N, triple super phosphate as P and potassium chloride as K. In all the experimental units was applied 2 kg&middotB&middotha-1 as boric acid. The components of production evaluated were dry matter of the head, total number of achenes, total achenes’ weight and 1000 achenes’ weight. The results of this research showed that nitrogen had a significant effect on the dry matter of the head, total number of achenes and total achenes’ weight. Phosphorus affected all production components and potassium affected the total number and the weight of achenes. With the exception of the 1000 achenes’ weight, all the production components of the sunflower increased with the increased ASW level influenced significantly at 0.01 level of probably the total number of achenes. The highest rates of N, P and K (100, 120 and 120 kg&middotha-1, respectively) and 100% of available soil water produced the highest production.

Growth of Pepper under Different Concentration of the Solutions Used in the Hydroponic System

Water availability is a fundamental condition for sustainable agriculture. However, a satisfactory water condition is not always possible in terms of quantity and quality in certain regions, such as the Brazilian semi-arid region. Thus, the purpose of this extremely important research was to evaluate the growth of cv. All Big with six combinations of wastewater plus saline (WW + SW) and two nutrient solution percentages, in a low-cost hydroponic system. The experiment was carried out in a greenhouse at the Department of Agricultural Engineering at Federal University of Campina Grande. A completely randomized experimental design was used, with treatments arranged in a factorial scheme (6 × 2), with 5 replications, being the treatments composed by the combination of six proportions of wastewater with saline water (50%/50%;60%/40%;70%/30%;80%/20%;90%/10%;100% of wastewater) and two nutrient solution concentration (80% and 100%), totalizing 60 experimental units. The biometric variables were analyzed at 55 and 96 days after sowing, namely: plant height (PH), stem diameter (SD), leaf number (LN) and leaf area (LA). The interaction between the concentration of the nutrient solution and the ratio of the saline water with wastewater was influenced in the behavior of peppers (cv. All Big) biometric variables. The nutrient solution prepared at 80% of its normal concentration had better performance in the development of plants when mixed with the proportions of water containing more wastewater. The proportion 30% saline water and 70% wastewater (30/70) with concentration of 80% of the nutrient solution obtained better satisfactory results in the studied biometric variables.