Agriculture consumes more than two thirds of the total freshwater of the planet. This issue causes substantial conflict in freshwater allocation between agriculture and other economic sectors. Regulated deficit irrigation (RDI) is key technology because it helps to improve water use efficiency. Nonetheless, there is a lack of understanding of the mechanisms with which plants respond to RDI. In particular, little is known about how RDI might increase crop production while reducing the amount of irrigation water in real-world agriculture. In this review, we found that RDI is largely implemented through three approaches: (1) growth stage-based deficit irrigation, (2) partial root-zone irrigation, and (3) subsurface dripper irrigation. Among these, partial root-zone irrigation is the most popular and effective because many field crops and some woody crops can save irrigation water up to 20 to 30 % without or with a minimal impact on crop yield. Improved water use efficiency with RDI is mainly due to the following: (1) enhanced guard cell signal transduction network that decreases transpiration water loss, (2) optimized stomatal control that improves the photosynthesis to transpiration ratio, and (3) decreased evaporative surface areas with partial root-zone irrigation that reduces soil evaporation. The mechanisms involved in the plant response to RDI-induced water stress include the morphological traits, e.g., increased root to shoot ratio and improved nutrient uptake and recovery; physiological traits, e.g., stomatal closure, decreased leaf respiration, and maintained photosynthesis; and biochemical traits, e.g., increased signaling molecules and enhanced antioxidation enzymatic activity.

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Regulated deficit irrigation for crop production under drought stress. A review

The Shotcrete Vegetation Mulching Technique (SVMT) was introduced to revegetate existing steep concrete-face slopes. By mixing cement and greening additives with hydraulic mulching materials in a particular proportion and directly spraying the mixture on steep concrete-face slopes, SVMT was proven to be superior to several traditional methods. SVMT can make a slope surface resistant to erosion within a short time (the uniaxial compressive strength of the slope was higher than 294.3 kN/m2 on the 14th day), create an environment suitable for plant growth (the vegetation coverage rate on the 90th day was higher than 90%) and foster a plant community capable of natural succession (competition and succession among Bermudagrass, turf-type tall fescue, hairy beggarticks, chamber bitter, oriental false hawksbeard, American burnweed, Pacific Island silvergrass, and inchplant were observed), effectively improving wildlife habitat and increasing biodiversity (small arthropods were found on the site, including spiders, grasshoppers, ants, ladybirds, etc.). Furthermore, the ecological engineering effects of SVMT on the experiment site were evaluated according to Mitsch and Jorgensen’s 19 Ecological Design Principles. It was found that the site treated with SVMT conformed to principles 2, 3, 8, 10, 11, and 16.

Effect evaluation of shotcrete vegetation mulching technique applied to steep concrete-face slopes on a highway of Taiwan

A state-of-the-art review on the advancement of sustainable vegetation concrete in slope stability

Canola is a cash crop produced for its highly-valued seed, and as a protein source for animal feed. While winter canola is produced mainly in the high plains, it is expanding to new environments, and is greatly incorporated into crop systems with advantages in terms of increasing crop yield and improving soil health. The objectives of this study were to evaluate eight winter canola genotypes for seed yield, and to determine their water productivity under semiarid climates and high elevations in the Four Corners region at Farmington, New Mexico. A field experiment was conducted at the New Mexico State Agricultural Science Center at Farmington for five growing seasons. Eight genotypes of winter canola (Baldur, Flash, Safran, Sitro, Virginia, Visby, Wichita, and Sumner) were arranged into the randomized complete block design. The field was fully irrigated with a center pivot irrigation system. Results showed that winter canola seed yield was dependent on genotype, varying from 2393 to 5717 kg/ha. The highest yield was achieved by Sitro, and the lowest yield by Sumner. There was inter-annual variation in canola nitrogen-use efficiency (NUE), irrigation water-use efficiency (IWUE), and crop water-use efficiency (CWUE). NUE varied from 12.9 to 50.4 kg seed/kg N, with the highest NUE achieved by Sitro, and the lowest by Sumner. IWUE varied from 0.34 to 0.80 kg/m3, and canola CWUE from 0.28 to 0.69 kg/m3. The highest water productivity was achieved by Sitro. The results of this study showed full assessment of canola production under the semiarid climate in the Four Corners region, and could improve crop productivity and profitability.

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Seed Yield and Water Productivity of Irrigated Winter Canola (Brassica napus L.) under Semiarid Climate and High Elevation

Impact of Irrigation, Nitrogen Fertilization, and Spatial Management on Maize

Effect of PRD (partial rootzone drying) on yield and yield components of canola (Brassica napus L.) was investigated in greenhouse conditions. The treatments were: T1, full watering of both sides of roots; T2, alternate irrigation on both sides; T3, half of irrigation water in T1 was given to one side; T4, same as T3 but without plate; T5, same as T2 but without plate. In T1, T2, and T3 treatments, the boxes were evenly separated into two compartments with thin plates. The results showed that grain yield of T1 to T5 treatments was 18.11, 16.38, 12.44, 9.29, and 8.66 g plant−1. T2 treatment increased plant height by 46.9% and 1000-seed weight by 17.8%, but reduced lateral branches by 16.7% and number of pods by 24%, over T1 treatment. T2 treatment was the most efficient (irrigation water use efficiency = 0.679 kg m−3) and treatment T5 was the least efficient (0.359 kg m−3). The difference between irrigation water use efficiency (IWUE) of T2 and T5, and T3 and T4 treatments, was significant (p < 0.05). Therefore, halving the amount of applied irrigation water and applying this water alternatively on both sides of the root zone will produce the highest IWUE. This study showed that PRD irrigation management has high influence on rooting system of canola. This phenomenon could affect nutrients uptake and consequently all aspects of plant growth and development.

Effects of partial rootzone drying on yield, yield components, and irrigation water use efficiency of canola ( Brassica napus L.)

Soil pollution is a highlighted concern of modern society, particularly in developing countries. The Drosh-Shishi valley, which is a hilly region near Afghanistan with a land area of around 15,000 km2, is situated in the south of Chitral District (Pakistan) and has a population of approximately 450,000. Nowadays, this region is being explored for soil pollution, specifically heavy metals which pose a potential risk to human health. Therefore, our main goal was to investigate possible sources of heavy metals’ spread and to assess the content levels in soil and the associated risks for human. We collected 34 representative samples from transported sediments and 31 from agricultural crops. We analyzed the soil samples for the contents of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn using ICP-OES analyzers. These values were used to obtain the contamination factor (CF) and to estimate the potential health risk caused by heavy metals according to the USEPA dose–response model. Our results suggest that the heavy metal pollution has a geogenic source, but it is also aggregated by chemical fertilizers used in farming. Regarding levels, most of the metals except Pb showed contents above the permissible level, with CF values from moderate to high. Overall, Cu and Ni showed a significant total cancer risk (TCR > 1 × 10−4) in children. Therefore, we conclude that heavy metal pollution is causing a serious threat to humans in this area, and we recommend that authorities should make more efforts in monitoring the heavy metals content in soils to reduce potential health risks.

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Assessment of the Ecological and Health Risks of Potentially Toxic Metals in Agricultural Soils from the Drosh-Shishi Valley, Pakistan

The Effects of Irrigation Methods and Water Quality on Soil Chemical Properties and Leaf Nutrient Uptake of Lavandula (Lavandula angustifolia L.) in an Arid Region

Receptor model-based approach to estimate urban road dust pollution by heavy metal(loid)s exposed to desert dust storms in a ra﻿pid-growing city of Iran

S. Soltani-Gerdefaramarzi

Papers

Effects of partial rootzone drying on yield, yield components, and irrigation water use efficiency of canola ( Brassica napus L.)

Assessment of the Ecological and Health Risks of Potentially Toxic Metals in Agricultural Soils from the Drosh-Shishi Valley, Pakistan

The Effects of Irrigation Methods and Water Quality on Soil Chemical Properties and Leaf Nutrient Uptake of Lavandula (Lavandula angustifolia L.) in an Arid Region

Receptor model-based approach to estimate urban road dust pollution by heavy metal(loid)s exposed to desert dust storms in a rapid-growing city of Iran

S. Soltani-Gerdefaramarzi

Papers

Effects of partial rootzone drying on yield, yield components, and irrigation water use efficiency of canola ( Brassica napus L.)

Assessment of the Ecological and Health Risks of Potentially Toxic Metals in Agricultural Soils from the Drosh-Shishi Valley, Pakistan

The Effects of Irrigation Methods and Water Quality on Soil Chemical Properties and Leaf Nutrient Uptake of Lavandula (Lavandula angustifolia L.) in an Arid Region

Receptor model-based approach to estimate urban road dust pollution by heavy metal(loid)s exposed to desert dust storms in a ra﻿pid-growing city of Iran

Receptor model-based approach to estimate urban road dust pollution by heavy metal(loid)s exposed to desert dust storms in a rapid-growing city of Iran