Typical engineering design of potato micro-sprinkler irrigation in Northern Shanxi

The Loess Plateau in the northern part of Shanxi Province has uneven rainfall and large evaporation, so droughts often occur. The drought has restricted the development of the local planting industry and the economy. Micro sprinkler irrigation has the advantages of strong adaptability, saving water, saving labor and land, increasing production, and preventing salinization, which is very suitable for this area. This micro-sprinkler irrigation design is carried out in typical plots, based on potato plant characteristics, rainfall data over the years, combined with corresponding specifications and actual conditions. This article uses a refraction micro-sprinkler with a spray diameter of 2.4 m. In the water transmission and distribution network, underground pipelines share 1,860 m of main pipes and sub-main pipes; surface pipelines share 1,200 m of branch pipes and 90,000 m of capillary pipes. The design meets the verification indicators of all irrigation groups, conforms to local actual conditions.

An effective evapotranspiration estimation scheme based on statistical indicators for sustainable environments in humid and semi-arid area of Khyber Pakhtunkhwa, Pakistan

Reference evapotranspiration (ETo) is critical for irrigation design and water management in rainfed and irrigated agriculture. The Penman-Monteith (FAO-56(PM)) equation was demonstrated to be the most reliable and adaptive to a wide range of humid to semi-arid climates. However, it requires several environmental parameters (e.g., wind speed, solar radiation), rarely available in developing countries. Therefore, numerous temperature-based formulas have been designed to address this issue for various environments. Their calibration and validation against the local climate frequently lead to increases in performance. We revised the Hargreaves exponent (EH) and substituted a value of (0.16) for the original value (0.5). The modified Hargreaves formula enhances the ETo predictions with a mean absolute error ranging from (0.791) mm per day for Balakot to (2.36) mm per day in Risalpur, averaging (3.797) mm per day, as compared to the Hargreaves-Samani (16.827) mm per day. In general, all the selected models showed high accuracy. However, the modified Hargreaves equation appeared to be the most promising results. It ranked first in (50%) of the whole area based on the standard error of estimate for estimating ETo in Khyber Pakhtunkhwa. Additional research must be conducted to determine the study's relevance to other regions.

Analysis of Furrow Irrigation Design Parameters On Sugarcane Growth And Yield Parameters Under Wonji Shoa Climatic Condition

Sugarcane is one of the important industrial crops produced all over the tropical areas. Sugarcane production is highly expanding in developing countries like Ethiopia. However, sugarcane is characterized by very high crop requirements. But sugarcane is produced mostly in Ethiopia using furrow irrigation methods in which more losses of irrigation water is most common due to many factors. Even if there are high losses of water in furrow irrigation, in which its performance influenced by many factors, to improve its performance or reduces the losses of irrigation water proper furrow irrigation decision variables combination is very important. In line with this the current study focused on three main furrow irrigation design parameters. The main purpose of the current study was to analyse effect of furrow irrigation design on sugarcane growth and yield parameters under Wonji Shoa Sugar Estate conditions. The field experiment was conducted using Split-split plot design with three factorial experiments replicated three times. All required data on growth and yield of sugarcane parameters were collected and analysed using SAS 9.4 version statistical software. The effect of furrow slope showed statistically significance variation at 5% significance on growth parameters (cane height, cane weight, cane diameter and number of cane internode per stalk), but non significance variation on yield components of sugarcane (moisture percent, dry substance, number of millable cane stalk and sugarcane yield). But the effect of furrow length showed statistically significance variation on almost all growth and yield parameters of sugarcane at 5% significance level except sugarcane yield. Finally, the effect of furrow discharge rate on all growth and yield parameters considered were showed statistically significance variation at 5% significance level except number of millable cane stalk. In general, the highest sugarcane yield was obtained from furrow slope three, furrow length three and furrow discharge rate as compared to the other factors level. Therefore, this result it can be recommended that slightly slope, longer furrow length and less properly applied discharge rate resulted in more yield of sugarcane.

Effects of Drip Irrigation Design on a Lemon and a Young Persimmon Orchard in Semi-Arid Conditions

Drip irrigation is presently widely recognized as the most efficient irrigation system that can be used in woody perennial crops. However, uncertainties exist on the more appropriate agronomic design to employ. Here, we summarized the research carried out for three seasons in two young woody perennial crops (persimmon and lemon) in southeastern Spain. Several irrigation designs were compared by maintaining a similar amount of water application but varying the number of emitters and pipelines in each row in the orchard. In the lemon trial, the agronomic irrigation design was additionally combined with different irrigation regimes, comparing full irrigation (FI) with sustained deficit irrigation (SDI). In the persimmon trees, which were still at the juvenility stage, varying the number of emitters per tree or the number of drip lines per tree row, neither affects tree performance nor fruit yield in two out of the three seasons. However, over the entire experimental period, the relative trunk growth increased when more emitters were employed. In the lemon trial, carried out with trees that had reached commercial production, the FI, compared with SDI, increased trunk growth and average fruit weight, while a reduced number of fruits per tree without affecting total yield was observed in the third year of experimentation. The number of emitters per tree only had an effect the first year, increasing lemon fruit weight when the number of drippers per tree increased. In addition, fruit composition was not consistently affected by the irrigation design. It is concluded that, for a given irrigation dose, irrigation frequency, and soil conditions (loam-clay texture), in both very young and more mature trees, increasing the number of emitters or the wetted area only had some slight positive effects on tree performance.

PREDICTING DRIP IRRIGATION CONTOURS OF CHERNOZEMS OF THE STEPPE TYPE OF SOIL FORMATION

Purpose: development and testing of a method for determining the size and moisture characteristics of moisture contours formed in the southern chernozems of the steppe type of soil formation during drip irrigation. Materials and methods. Experimental studies were carried out on light, medium and heavy loamy medium thick ordinary and southern chernozems. The vertical sections of humidification zones with a system of in-contour moisture isopleths were considered. As indicators determining the contour parameters, the following are considered: the content of physical clay in the moistened soil layer, the soil density and its lowest moisture capacity. Results. In the process of studying the experimental vertical sections of soil drip moistening zones, dependences characterizing the existing functional relationships between the contour geometric parameters and the characteristics of soil, phytosoil and technological conditions of their formation were determined. On the basis of the obtained experimental dependences, a method for calculating the contours linear dimensions and graphically constructing their outlines has been developed. The proposed method for contour predicting was tested on actual data on their sizes and moisture distribution in the inner-contour space, obtained by other researchers experimentally. Comparison of the experimental and predicted contours of drip moistening testifies to their qualitative similarity both in terms of the external outline and in terms of the location of isopleths with different levels of soil moisture inside the wetted zone. The calculated value of the irrigation rate differs from the actual one by 2.2 %. Conclusions. The proposed method for predicting the sizes of moisture contours and intra-contour isopleths, formed in chernozems of the steppe type of soil formation, was developed to the level of calculations using the author's computer program. An example of approbation of the proposed method indicates its acceptability for use in the crops drip irrigation design and operational practice.

Parameter estimation of soil hydraulic characteristics by inverse modeling of the analytical equation for unsaturated subsurface water flow

In drip-irrigated systems, the understanding of the soil wetting pattern is essential in defining the area effectively irrigated, the spacing between the emitters and their installation depth, and the irrigation rate. Thus, this study aims to estimate soil hydraulic characteristics through inverse modeling of an analytical equation used in wetting bulb simulation based on soil moisture measurements obtained in the field. The parameters of the Gardner model, which describes the unsaturated soil hydraulic conductivity, and the van Genuchten model that describes the soil moisture retention curve, were estimated by inverse modeling techniques. The following options were considered: (A) estimating parameter β while considering the other parameters, Ko, θr, θs, α, n, and m, as known and obtained experimentally; (B) estimating parameters Ko and β while considering the experimental retention curve as known; (C) estimating parameters Ko, β, α, n, and m while considering the values of the θr and θs volumetric moisture as known; (D) estimating all the parameters of Gardner and van Genuchten models (Ko, θr, θs, α, n, and m). The results indicate that option D showed better concordance between the estimated and observed moisture values. Thus, the inverse modeling of the analytical equation is an important tool for irrigation design and management.