Due to increases in water demand—caused by escalating increases in population and water deficiency and scarcity—and due to the increase in climate change and global warming impacts, much focus has been directed to regional and national drought policies related, particularly, to water resources and agriculture. This paper aims to review the consequences and impacts of droughts on pest outbreaks. The approaches presented herein demonstrate various actions to be taken in order to limit drought outcomes and the impacts of pests. In Australia alone, the analyses showed that drought caused approximately a $7.4 billion drop in the agricultural sector. Accordingly, drought can be considered as one of the major causes of agricultural pests. To manage them, biological controls and self-reliance for drought are the best and most inexpensive approaches to be taken within the framework of an integrated pest management scheme. Australia and the State of Palestine were selected as case studies for investigation in this study, because both regions have common problems related to water resources and water scarcity. In addition, although both regions suffer droughts, they have developed different adaptation measures, which are affected by different political and socioeconomic influences, with the aim of supporting farmers, who are unable to maintain feed to their livestock and take care of their agricultural crops and yields (plant production). Breakthrough offers new hopes for global food security, as parts of wheat that relate to coeliac disease and other allergies can now be tracked. Some solutions are suggested in this study, and the national drought policies in both regions are investigated and analyzed.

Solute runoff and leaching are two direct pathways of nutrient pollution from paddy fields into water systems. Due to the dynamic nature of paddy fields, solute transport and transformation processes are complex and difficult to understand. Therefore, in this study, nitrogen (N) transport in flooded paddy rice fields with conventional irrigation (flooding irrigation) in the Tanjung Karang Rice Irrigation Scheme (TAKRIS), Sawah Sempadan, were observed and modelled using the Hydrus-1D numerical model during two consecutive rice growing seasons. Based on solute transport analysis results, it was observed that 50.3% to 48% of percolated N was accumulated in the top 40-cm soil layer, while 49.7% to 52% of leachate N was lost below the 40-cm soil layer (40–100 cm) during the off and main seasons, respectively. About 85% of N leaching loss was in the form of NO₃⁻. NO₃⁻ was absorbed by rice roots within 0–40 cm and the denitrified root zone; however, there was still a large quantity of NO₃⁻ which remained below the root zone, which was quickly transported downward along with the leachate water. The NH₄⁺ concentration in subsurface water was lower than the NO₃⁻ concentration due to various processes that removed NH₄⁺ from the topsoil layer (0–40 cm), such as ammonium volatilisation, nitrification, and plant uptake. The total leaching loss of N was 34.9 and 27.9 kg/ha during the off and main seasons, respectively. The simulated and observed water flow and nutrient leaching were in a good agreement (R² = 0.98, RMSE = 0.24). The results showed that Hydrus-1D successfully simulated the solute movement under different soil depths during the study period.

A quantitative estimation of the major components of the field water balance provides management decisions on how the scheme ought to be operated to ensure better distribution of irrigation water and increased delivery performance. Therefore, in this study, the water balance component in transplanted and broadcasted rice fields with conventional irrigation (flooding irrigation) in the Tanjung Karang Rice Irrigation Scheme (TAKRIS), Sawah Sempadan were observed and then modeled using Hydrus-1D numerical model during two consecutive rice growing seasons. During the off-season, irrigation water accounted for 59.6% of the total water input (irrigation + rainfall), but about 76.2% of total water input during the main season. During the main season, rainfall water only contributed to 23.8% of total water input and 40.4% during the off-season. Drainage water accounted for 37.3% of the total water input during the off-season and 43.7% during the main season, respectively, which was the main path of water losses from conventional rice fields, which indicates that maintaining a high water level and huge rainfall events during both seasons increased drainage water. Simulated ET during the off-season and the main season accounted for 38.1% and 49.5% of the total water input, respectively. Observed and simulated water percolation revealed about 17.1% to 19.2% of total water input during both seasons, respectively. Additionally, the water productivities analyzed from total water input and irrigation water were 0.43 and 0.72 kg m⁻³ during the off-season and 0.60 and 0.78 kg m⁻³ during the main season, respectively. The water productivity index evaluated from observed and modeled evapotranspiration was 1.03 and 1.13 kg m⁻³ during the off-season and 0.98 and 0.94 kg m⁻³ during the main season, respectively. The overall results revealed that Hydrus-1D simulations were a reasonable and effective tool for simulating vertical water flow in both broadcasted and transplanted rice experimental fields.

Nitrogen loss from agricultural fields results in contamination of ground and surface water resources due to leaching and runoff, respectively. Nitrogen transport dynamics vary significantly among agricultural fields of different climates, especially in the tropical climate. This study intended to evaluate the rainfall impact on nitrogen distribution and losses under tropical rain-fed conditions. The study was carried out in a sweet corn field for two growing seasons at the Malaysian Agricultural Research and Development Institute (MARDI) research field. The HYDRUS-1D numerical model was used to simulate nitrogen transport dynamics in this study. The observed nitrogen concentrations were used for calibration and validation of the model. Total nitrogen input to sweet corn was 120 kg/ha for both seasons. Nitrogen losses through surface runoff and leaching were dominating pathways. Surface runoff accounted for 35.3% and 22.2% of total nitrogen input during the first and second seasons, respectively. The leaching loss at 60 cm depth accounted for 4.0% (first season) and 18.5% (second season). The crop N uptake was 37.5% and 24.9% during the first and second seasons, respectively. Nitrate was the dominant form of N uptake by the crop that accounted for 83.6% (first season) and 78.5% (second season). The HYDRUS-1D simulation results of nitrogen concentrations and fluxes were found in good agreement with observed data. The overall results of simulation justified the HYDRUS-1D for improved fertilizer use in the tropical climate.

Despite many studies on the hydrological responses to forest cover changes in micro and mesoscale watersheds, the hydrological responses to forest cover alterations and associated mechanisms through the large spatial scale of the river watershed have not been comprehensively perceived. This paper thus reviews a wide range of available scientific evidence concerning the impacts exerted by the forest removal on precipitation, water yield, stream flow, and flow regimes. It is concluded that there is no statistical correlation between forest cover and precipitation and water yield at the micro and mesoscale. In contrast, there is a relative correlation coefficient ( r = 0.77, p < 0.05) between forest cover and water yield at large scales (>1000 km2). These findings help our understanding of the hydrological response to forest disturbance at large and regional scale and provide a scientific perception to future watershed management in the context of human activities and natural hazards.

The water retention curve (WRC) determines important properties of growing media with respect to water dynamics. However, the standard laboratory determination is time-consuming and laborious. The objectives of this study were (i) to test the practical applicability of the centrifuge method as a quick test for a wide range of growing media, (ii) to compare a simple substitution method to describe the bulk density of growing media with the results of the standard method, and (iii) to give a recommendation under which conditions (the mean weighted diameter of the substrate particles is 5 mm or less) the centrifuge quick test could serve as a replacement for the standard DIN method. Water content vs. water suction values determined for the whole range of the water retention curve with the standard method, and centrifugation results were compared and evaluated by correlation analyses. The results showed good agreement (R² ≥ 0.98) between the centrifuge and DIN methods, with the effect of material compression in the centrifuge method resulting in a statistically significant correlation between compression and bias at low pF stages. This, however, did not lead to significant deviations between the method’s results at low pF stages (<pF 2.0). The method’s rapidity (2 days vs. up to 8.5 days) and correlation with standard methods highlight its potential for practical applications. Limitations, such as compression effects, were noted, emphasizing the need for careful interpretation. Overall, the centrifuge method provided a valuable research and substrate development tool. This study contributes to refining measurement techniques in growth substrates, encouraging ongoing research in water dynamics in growing media.