Euler Soares Franco

Comparação de indicadores químicos do solo após o plantio da algaroba

A algaroba (Prosopis sp) foi trazida para o Semiarido Brasileiro como o objetivo de alimentar os rebanhos nos periodos mais secos do ano. Com o objetivo de avaliar parâmetros quimicos em solos cultivados com esta cultura, foi conduzido um experimento junto a area experimental do Departamento de Engenharia, UFCG, Universidade Federal de Campina Grande, Estado da Paraiba. No experimento foi utilizado um delineamento estatistico casualizado, com um esquema fatorial de 5 x 2, com 4 repeticoes, com 5 niveis de reposicao de agua (W1= 20% ate W5 = 100% da evapotranspiracao) e 2 tipos de solo. Em 92,5% dos lisimetros as analises mostraram que houve um aumento da fixacao no nivel de nitrogenio no solo. Ja com relacao ao teor de materia orgânica os resultados que foram encontrados no experimento, mostraram que 95% dos lisimetros apresentaram um acrescimo no valor da percentagem de materia orgânica, quando comparados com os resultados obtidos no inicio do experimento. Com os resultados obtidos ao final do experimento constatamos que a algaroba trouxe beneficios no tocante a melhoria na qualidade do solo.

Evaluation of the levels of nitrogen, organic matter and pH in sols cultivated with Prosopis

Prosopis crop was introduced in the Northeast region in Brazil with the objective to feed the livestock during the drier season. However, after 30 years, it was created a big polemic around it. Current the crop is considered as a plague. With the objective to evaluate the levels of nitrogen and organic matter and the content of pH in sols cultivated with Prosopis it was carried out an experiment between July 15th 2007 and September 30th 2008. The experimental design was in randomized block in a factorial scheme 5 x 2, with 4 repetitions, and five levels of soil available water at the irrigation management level (W1= 20% to W5 = 100% of the evapotranspiration rates) and two different soils. These when analyzed at the beginning of the experiment presented pH above 8,0, however at the end of the experiment when they were analyzed again, it was observed that in 65% of the lysimeters the pH was under 8,0 and reach a lower index of 7,1. In 92,5 of the lysimeters the level of nitrogen in the soil increased, which indexes at the begin was 0,04% and at the end of the experiment value of 0,06%, it increased in the rate that ranges from 33,3% to 66,6% respectively. In relation to the content of organic matter, it was observed that in 95% of the lysimeters there was an increase on it, when compared with the results that was found in the begin of the experiment. The values ranged from 0,86% to 2,19%, it means that there was an increase of 13,95% to the low value found and 66,21% to the bigger one. These results are according to other studies that in soil with prosopis crop there is an increase in the levels of organic matter, it is probably because of the leaves and branches that fall which protect the soil.

Adjustment of Infiltration Curve Through Non-Linear Regressions

The objective of this study was to estimate the water infiltration in the soil through fittings of non-linear functions and empiric models proposed by Horton, Kostiakov and Kostiakov-Lewis and to compare the results with field data obtained using the ring infiltrometer. The experiment was conducted in sandy soil of the experimental area of the State Enterprise of Agricultural Research, located in Lagoa Seca city, Paraiba State, Brazil. It was performed 65 ring infiltrometer infiltration tests along the experimental area. The models of Horton, Kostiakov and Kostiakov-Lewis, as well as the non-linear regressions functions (exponential and potential), were adjusted to data obtained in field. The procedure using non-linear regressions showed better estimates than the empiric models, having the potential and exponential functions presented values for R2 equal to 0.997 and 0.971, respectively. Among the empiric models, the model proposed by Horton was the one that presented the best performance. However, the predictions of empiric models and of non-linear regressions were practically similar. The procedure of non-linear regressions presents methodological advantages, as well as a substantial reduction of time and cost to determine the soil water infiltration rate.

Growth Analysis of Castor Oil Plant, Cultivar BRS 149 Northeastern, Under the Effect Irrigation Treated Wastewater

The objective of this research was to evaluate the levels and types of different treated wastewater from industry and their effects on the growth and development of Northeastern BRS 149 castor oil plant. The experiment was carried out at the greenhouse of the Cotton Research National Center CNPA/EMBRAPA, in Campina Grande city, Paraiba state, Brazil. The experimental design was in randomized block in a factorial scheme [(4x3) +3] with three repetitions, with the following factors: three types of wastewater and one of provisioning water (A1= IPELSA – Cellulose and Paper Industry; A2 = COTEMINAS; A3 = ILCASA and A4 = provisioning water), three levels of soil available water (N1 = 100%, N2 = 80% and N3 = 70% of the soil available water) and three controls for the three levels of soil available water, using provisioning water with NPK inorganic fertilizers (AC4), in which the source of nutrients were sulphate of ammonia (20%N), super phosphate triple (43% P2O5) and potassium chloride (60% K2O). In order to evaluate the growth, it was made biweekly measures during 135 days after planting, where the following variables were measured: height of plant (HP), diameter of steam (DS) and total foliar area (TFA). The four different types of water showed significant statistical differences, observed in the growth variables. It was observed that the three wastewater (A1, A2, A3), due to its high concentration of nutrients, increased all growth variables, comparing to provisioning water without fertilizer (A4). A statistical difference was observed among the four different types of water (A1, A2, A3, A4) and provisioning water AC4 with fertilizer.