Water Management for Sustainable Food Production

A Prototype for an Intelligent Water Management System for Household Use

Water scarcity is becoming an issue of more significant concern with a major impact on global sustainability. For it, new measures and approaches are urgently needed. Digital technologies and tools can play an essential role in improving the effectiveness and efficiency of current water management approaches. Therefore, a solution is proposed and validated, given the limited presence of models or technological architectures in the literature to support intelligent water management systems for domestic use. It is based on a layered architecture, fully designed to meet the needs of households and to do so through the adoption of technologies such as the Internet of Things and cloud computing. By developing a prototype and using it as a use case for testing purposes, we have concluded the positive impact of using such a solution. Considering this is a first contribution to overcome the problem, some issues will be addressed in a future work, namely, data and device security and energy and traffic optimisation issues, among several others.

Automatic Crop Canopy Temperature Measurement Using a Low-Cost Image-Based Thermal Sensor: Application in a Pomegranate Orchard under a Permanent Shade Net House

Water scarcity in arid and semi-arid areas has led to the development of regulated deficit irrigation (RDI) strategies on most species of fruit trees in order to improve water productivity. For a successful implementation, these strategies require continuous feedback of the soil and crop water status. This feedback is provided by physical indicators from the soil-plant-atmosphere continuum, as is the case of the crop canopy temperature, which can be used for the indirect estimation of crop water stress. Infrared Radiometers (IRs) are considered as the reference tool for temperature-based water status monitoring in crops. Alternatively, in this paper, we assess the performance of a low-cost thermal sensor based on thermographic imaging technology for the same purpose. The thermal sensor was tested in field conditions by performing continuous measurements on pomegranate trees (Punica granatum L. 'Wonderful') and was compared with a commercial IR. A strong correlation (R² = 0.976) between the two sensors was obtained, demonstrating the suitability of the experimental thermal sensor to monitor the crop canopy temperature for irrigation management.

Effect of agricultural activities on surface water quality from páramo ecosystems

Páramos are high mountain ecosystems strategic for water provision in South America. Currently, páramos are under threat due to agricultural intensification that impairs surface water sources. This research analyzed the effect of agriculture (spring onion-Allium fistulosum, potato-Solanum tuberosum, and livestock farming) on water quality in páramo ecosystems. A Hydrographic Unit upstream of the Jordan river catchment (Colombia) was selected and monitored in two different rainfall regimes, following the paired catchments and upstream-downstream approaches to compare water quality from natural and anthropic areas. Twenty-two parameters related to agricultural activities were analyzed (nutrients, salts, organic matter, sediments, and pathogens). The studied agricultural activities increased loads of surface water in quality in nitrates (0.02 to 2.56 mg N-NO₃/L), potassium (0.13 to 1.24 mg K/L), and Escherichia coli (63 to 2718 FCU/100 mL), generating risks on the human health and promoting eutrophication. Total nitrogen and organic matter in the rainy season were higher than dry. BOD₅, COD, turbidity, and E. coli were above international standards for direct human consumption. However, water could be used for irrigation, livestock watering, and aquatic life ambient freshwater. The results show that a small land-use change of almost 15% from natural páramo vegetation to agricultural uses in these ecosystems impairs water quality, limiting its uses, and the need to harmonize small-scale livelihoods in the páramo with the sustainability of ecosystem service provision.

Effects of Water and Nitrogen Management on Water Productivity, Nitrogen Use Efficiency and Leaching Loss in Rice Paddies

Effective water and nitrogen (N) management strategies are critical for sustainable agricultural development. Lysimeter experiments with two deep percolation rates (low percolation and high percolation, i.e., LP and HP: 3 mm d−1 and 5 mm d−1) and five N application levels (N0~N4: 0, 60, 135, 210 and 285 kg N ha−1) were conducted to investigate the effects of controlled drainage on water productivity (WP) and N use efficiency (NUE) in water-saving irrigated paddy fields. The results demonstrated that NH4+-N and NO3−-N were the major components of total nitrogen (TN) in ponded water and leachate, accounting for more than 77.1% and 83.6% of TN, respectively. The risk of N leaching loss increased significantly under treatment of high percolation rates or high N application levels. High percolation loss required greater irrigation input, thus reducing WP. In addition, N uptake increased with increasing N application, but fertilization applied in excess of crop demand had a negative effect on grain yield. NUE was affected by the amount of N applied and increased with decreasing N levels. Water and N application levels had a significant effect on N uptake of rice, but their interaction on N uptake or NUE was not significant. For the LP and HP regimes, the highest N uptake and WP were obtained with N application levels of 285 kg ha−1 and 210 kg ha−1, respectively. Our overall results suggested that the combination of controlled drainage and water-saving irrigation was a feasible mitigation strategy to reduce N losses through subdrainage percolation and to provide more nutrients available for rice to improve NUE, thus reducing diffuse agricultural pollution. Long-term field trials are necessary to validate the lysimeter results.

Accumulation and translocation of eight trace metals by the different tissues of Abelmoschus esculentus Moench. irrigated with untreated wastewater

Due to water scarcity, the use of wastewater to irrigate crops is on the rise all over the world, including in Egypt (particularly untreated wastewater). The purpose of this study is to see if irrigation with untreated industrial wastewater in natural fields can cause Abelmoschus esculentus Moench. (okra plant) to accumulate and translocate eight trace metals (lead: Pb, cadmium: Cd, chromium: Cr, copper: Cu, iron: Fe, manganese: Mn, nickel: Ni, and zinc: Zn) in its different tissues. It was extended to look at the effects of wastewater irrigation on the farmed okra plants' growth characteristics, nutrients, colors, and organic content. Two studied sites at South of Cairo have been investigated: the first site (29°42'31.17" N and 31°15'11.56" E) represented by five cultivated fields irrigated with Nile water (control) and the second site (29°42'37.87" N and 31°17'14.53" E) fields irrigated with effluent received untreated industrial wastewater. Three composite soil and irrigated water samples were collected from each site. Because of wastewater irrigation, soil and plant nutrients (nitrogen, potassium, and phosphorus) decreased significantly (at P < 0.01), whereas trace metals increased significantly (at P < 0.01 and P < 0.05) for soil and plant samples irrigated with untreated wastewater. Due to irrigation with untreated wastewater, there was also a significant decrease in okra growth metrics (at P < 0.05) and leaves photosynthetic pigments: chlorophyll a and b, and carotenoids (at P < 0.01 and P < 0.05). In the plant's fruits (edible section) watered with wastewater, iron was the most abundant metal. Besides, Cd, Cu, Fe, Mn, Ni, and Zn concentrations were also in the phytotoxic range (42.57, 140.67, 2756.67, 1293.33, 1326.67, and 877.83 mg kg^-1, respectively). All trace elements examined accumulate in the roots of wastewater irrigated okra (Bioaccumulation factor > 1). Okra plants, on the other hand, did not have an accumulated trace metals strategy in their shoots since the translocation factor was less than one. Because of substantial trace metal accumulation in their edible sections, the scientists advised against eating okra plants grown in fields watered with untreated wastewater.

Preparation of thermosensitive buprofezin-loaded mesoporous silica nanoparticles by the sol-gel method and their application in pest control

BACKGROUND

Environmental stimuli-responsive release is one important way to reduce the dosage of pesticide, increase the usage efficiency and improve environmental compatibility.

RESULTS

On this basis, we synthesized mesoporous silica nanoparticles (MSNs) and modified them to develop a thermosensitive pesticide controlled release formulation (CRF). In this study, MSNs prepared by the sol-gel method were used as the core, poly (N-IsoPropylAcrylaMide) [P (NIPAM-MAA)] was used as the shell, and buprofezin (Bup) was loaded by adsorption. The prepared Bup@MSNs@P(NIPAM-MAA) could effectively prevent the degradation of buprofezin under UV light and exhibited excellent adhesion to rice leaves. The bioassay results showed that the mortality of Nilaparvata lugens (Stål) treated by Bup@MSNs@P(NIPAM-MAA) was positively correlated with temperature, resulting mainly from the change of release amount of buprofezin caused by temperature variation. Bup@MSNs@P(NIPAM-MAA) had long duration (20 days) for controlling N. lugens, and did not hinder the growth of rice. Meanwhile, Bup@MSNs@P(NIPAM-MAA) had low toxicity to zebrafish and human pneumonocyte BEAS-2B cells.

CONCLUSION

This novel thermosensitive pesticide CRF can be applied widely to other insecticides, thus greatly promoting the development of intelligent pesticide formulations. © 2021 Society of Chemical Industry.