Analysis of Soil Texture, Furrow Geometry, and Infiltration Rate for Improving Water Application Efficiency

Soil texture, furrow geometry, and infiltration rate are the main characteristics for improving water application efficiency. Substantial amounts of diverted irrigation water are often lost because of poor water control, inefficient irrigation conveyance systems, poor on-farm water management, or poor application practices. Field experiments were conducted on three farm plots within the command area for water availability and accessibility under the Melka Hida small-scale irrigation scheme in the West Guji Zone of Oromia Region, Ethiopia. The physical characteristics of soil, including depth, particle distribution, textural classification, bulk density, field capacity, and permanent wilting point, were studied and the results are presented. Furrow parameters including slope, width, length, and shape geometry were measured. The cumulative infiltration and infiltration rates were also recorded. The results show that irrigation application efficiency ranged from 57 to 64% with an average of 61%, indicating that about 40% of the applied water was not used by crops. The storage efficiency ranged from 79.6 to 81.6% with an average of 80%. Soil moisture measurements showed that crops were water stressed during the experimental period. Application efficiency decreased with increasingly steep slopes and cutoff times, greater applied depth, and high inflow rate in the study area. Unavailability of irrigation water control structure, weakness of water users’ associations, and maintenance of furrows and steep slopes were observed as the major causes of inefficient water management in the Melka Hida irrigation scheme.

AVALIAÇÃO DE KIT DE IRRIGAÇÃO POR GOTEJAMENTO UTILIZANDO ÁGUA RESIDUÁRIA

AVALIAÇÃO DE KIT DE IRRIGAÇÃO POR GOTEJAMENTO UTILIZANDO ÁGUA RESIDUÁRIA ROBERTA DANIELA DA SILVA SANTOS1; REGIANE DE CARVALHO BISPO1; KEVIM MUNIZ VENTURA1; MARCELLO HENRYQUE COSTA DE SOUZA1 E MARIANA ALEXANDRE DE LIMA SALES1 1Programa de Pós-Graduação em Irrigação e Drenagem, Universidade Estadual Paulista “Júlio de Mesquita Filho”- UNESP/FCA, Rua Dr. José Barbosa de Barros, 1780, Botucatu, SP, [email protected], [email protected], [email protected], [email protected], [email protected] 1 RESUMO A produtividade agrícola em sistemas irrigados está diretamente relacionada com a uniformidade de distribuição de água para as plantas. Avaliar periodicamente essa distribuição de água é fundamental, pois a irregularidade desse parâmetro, pode causar desperdícios de água e energia, além de prejudicar a rentabilidade da propriedade. Desta forma, o objetivo deste trabalho foi comparar a eficiência de aplicação de água do kit de gotejamento – Dripkit, novo e após 15 meses instalado em campo, operando com água residuária tratada. A avaliação foi realizada no Laboratório de Hidráulica do Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas – FCA/UNESP, campus Botucatu-SP e foi conduzido conforme as recomendações da Norma ISO 9261:2004, utilizando água de abastecimento público, fornecida pela Companhia de Saneamento Básico do Estado de São Paulo (Sabesp). A avaliação foi realizada na bancada de ensaios para tubos gotejadores e foram calculados os coeficientes de uniformidade de Christiansen, de distribuição, de uniformidade estatístico e eficiência de aplicação. Na mangueira usada, os parâmetros CUC, CUD, CUE e EA, foram classificados como ruim, razoável, inaceitável e inaceitável, respectivamente.Palavras-chave: Irrigação localizada, uniformidade, distribuição, eficiência de aplicação. SANTOS, R. D. S.; BISPO, R. de C.; VENTURA, K. M.; SOUZA, M. H. C.; SALES, M. A. L.EVALUATION OF A DRIPPING IRRIGATION KIT THAT USES WASTEWATER 2 ABSTRACT Agricultural productivity in irrigated systems is directly related to the uniformity of distribution of water to the plants. The periodical evaluation of this water distribution is fundamental, since an irregularity in this parameter may waste water and energy, as well as undermine the profitability of the property. In this way, the purpose of this work is to compare the water application efficiency of the drip kit – Dripkit after 15 months of use in the field, operating with treated wastewater. The test was carried out in the Hydraulic Laboratory of the Department of Rural Engineering of the Faculty of Agronomic Sciences - FCA / UNESP, Campus Botucatu-SP and was conducted in accordance with the ISO 9261: 2004 standards, using potable water. The evaluation was performed on a test bench for dripping irrigation and the uniformity, Christiansen, distribution and statistical coefficients were calculated. The CUC, CUD, CUE and EA parameters were classified as bad, regular, unacceptable and unacceptable, respectively. Keywords: Drip irrigation, uniformity, distribution, application efficiency.

Corn yield under various simulated irrigation depths

ABSTRACT Mathematical models are tools to estimate and understand system behaviors against diverse situations; they may help in decision-making through simplified representations of the reality, allowing simulating various scenarios and estimating impacts of different courses of action on production systems, assisting thus in activity planning. Thus, this paper proposed a simulation of corn crop yields according to different field experiment characteristics and weather conditions in which it was conducted, with the purpose of setting a simulation model already calibrated and tested for corn crop cycle in the region of Santiago – RS, Brazil. The increasing water levels had a positive effect on grain yield and corn dry matter. On the other hand, a level of 800 mm reduced corn yield, as well as water application efficiency decreased from 550 mm. The proposed model can be used as a tool for regional planning in corn crop implementation under irrigation and enables identifying irrigation strategies for high grain yields, being considered a tool for yield prediction in irrigated crops.