Sunny Goh Eng Giap

Comprehending sediment transport dynamics is crucial for forecasting morphological changes in aquatic and terrestrial ecosystems, especially where hydrodynamic factors like tides or surface runoff markedly affect sediment redistribution. This research employs a one-dimensional (1D) numerical model that integrates the Saint-Venant shallow water equations with sediment transport equations, using the Exner equation for bed evolution and the advection-diffusion equation for suspended load. Bedload transport is characterized by the Grass equation, which models sediment flux as a function of depth-averaged velocity and an empirical coefficient (Ag) that incorporates a combined effects of many physical properties on sediment transport. Simulations were performed over diverse tidal ranges, durations, Grass coefficient, and bed friction coefficients (Cf) to evaluate their singular impacts on sediment dynamics. Results indicated that prolonged simulation durations and heightened tidal amplitudes exacerbated sediment redistribution and bedform flattening, signifying cumulative morphological changes over time. Elevated Grass coefficient and friction coefficient values substantially impacted bed stability, with high Ag values promoting sediment mobility and high Cf acting as a regulator of shear stress and reduce erosion intensity. Sensitivity analysis indicated that Ag is the most significant parameter influencing morphological change. These findings hold significant significance for agricultural soil erosion research, as analogous mechanisms of sediment displacement regulate both natural and managed systems. The coefficients for Grass and friction can be modified to reflect surface conditions, including vegetation cover and tillage methods on agricultural lands. This underscores the potential for interdisciplinary application of hydrodynamic sediment models to guide erosion control measures and sustainable land use planning. The study recommends extending the model to study and facilitating its practical application in erosion monitoring and agricultural management systems.

Agroecology is relatively a new term for local community in Malaysia. For agroecology practices to be widely accepted require better understanding of what it is, what are the agroecological attributes, and what are those elements in agroecology. In general, agroecology has ten elements, and it appears none or impossible nearly for any agricultural practices to fully comply with all these elements, but perhaps a combo high number of elements at certain degree of trade-off among those elements would be a feasible approach. In this study, we revealed some of the published practices available in Malaysia, as an example. The intention of the review effort is to reveal where we are currently, and how to move forward. Four case studies are discussed. First, agroecology approaches for cereal crops revealed up to four elements of agroecology have been implemented in the plantation, but also some elements remain unexplored. Second, a comparison has been made between the paddy cultivation by agroecology with conventional cultivation. Agroecology method in paddy farm have shown to save cost, environmentally friendly, and generate produced with better health benefit over the conventional method. Third, the examples of agroecological practices in oil palm plantation displayed many impressive solutions in line with agroecology, but similar with cereal crop practices that it has a limited inclusion of agroecology elements. Some of the agroecology elements can be explored further for implementation in agriculture are resilience, human and social values, culture and food traditions, responsible governance, and circular and solidarity economy.

Agroecology has ten elements that can be implement in the agricultural activities and food systems to achieve a more sustainable future in producing and consuming foods. Water saving is one of the important attributes of agroecological practices. In this study, we are investigating soil series information provided by the Department of Agriculture, Malaysia. There are 34 soil series identified in Pahang state. The existing information provided with the soil series do not guide the implementation of irrigation management in terms of water consumption requirement for plantation land management. The current study converts soil series information into soil textures. There are seven soil textures determined in Pahang states. They were Clay, Silty Clay, Clay Loam, Silty Clay Loam, Sandy Clay Loam, Loam, and Sand. Soil textures were used to estimate soil hydraulic properties to represent the soil series. Soil field capacity, permanent wilting point, and plant available water were determined. Water infiltration simulation was carried out on all soil textures, and it was found silty clay loam (Gugut Series, Setol Series) was one of the best soil textures in terms of water infiltration time, and water retention in the soil. The information derived from the current study can be used for land management planning to estimate the irrigation water supply needed, which will be useful for cost estimation and water resource management.

Soil bulk density is an important aspect of soil properties, and it can affect agroecology as in diversity, synergies, efficiency, recycling, and resilience. Diversity as in soil low in bulk density allows greater penetration of plant roots allow better access of water and nutrients. The synergistic effect of adequate supply of soil moisture content in forming moderately low soil bulk density for deeper plant roots for better access to water and nutrients. Agroecology efficiency reduces the need of external inputs to reduce environmental impact related to the resulted excessive pollution and wastage. Ultimately, an improved soil bulk density may increase the overall agroecosystem resilience and output, thus, improving the efficiency. Recycling in agroecology involved mass recycling and heat circulation as in nutrient, water, and waste reduction. A high soil bulk density will impede the recycling process the soil. Resilience as in drought resistance is for soil not too loosely packed that cannot hold water or too compacted until flooding water occurs at the surface and too little water infiltrates the soil. In addition, soil bulk density can affect the estimation of soil moisture content and temperature distribution. The ability to understand the factors that influence changes in soil bulk density would improve the predictive ability of the current model. The current study conducts a review on factors affecting the soil bulk density that is divided into soil physical, chemical, biological, environmental, and management practices. A cumulative of more than 50 factors are discussed in the review on how it affects the change in soil bulk density. The current review illustrates the conceptual relation of these factors on soil bulk density. Also, the result of the current work can be used to support future endeavour by turning the conceptual relation into quantifiable predictive model.

Soil water vapor movement carries mass of water and its bulk quantity in motion carries a specific amount of energy. The moment when water molecules obtain enough energy to release themselves from liquid surface, it involves phase transition from liquid to gas phase. The energy required for its release or freedom must be sourced from some energy source in the soil. The energy can come from the soil, water, or gas phase in the immediate surrounding. As such, the water phase transition into gas phase absorbs energy and causes temperature variation. Since vapor carries a significant amount of energy, its evaporation can cause a significant amount of temperature in the soil. Hence, studying vapor movement in soil and the factors affecting vapor movement is an important subject of concern. The current study is looking into factors that affect soil water vapor movement in the soil. The equation from Philip and de Vries was examined in the current study. We found that soil water vapor movement was not limited to factors affecting vapor phase, the vapor phase was in continuous interaction with other factors that affecting liquid water movement and heat flux in the soil.

A study was conducted to determine the effect of potassium (K) with organic fertilizers on the growth, yield and sweetness of reddish waxy corn. The treatments were: (T1) standard fertilizer rate of 60 kg ha-1 K2O without organic fertilizer (control); (T2) 30 kg ha-1 K with organic fertilizer; (T3) 90 kg ha-1 K with organic fertilizer and (T4) 120 kg ha-1 K with organic fertilizer. Organic fertilizer used was 1.5 t ha-1 Bokashi and 20 t ha-1 chicken manure biochar (CMB). The planted corn received 120 kg ha-1 N and 60 kg ha-1 P2O5. The experimental design was Completely Randomized Design (CRD) with six replications. Stem girth, number of leaves, the height of the first cob, fresh weight of the first cob, 100 grains weight, cob girth, cob length and sweetness (Brix scale, %) data were analyzed using ANOVA (Analysis of Variance) at 5% significant levels. The Least Significant Different (LSD) was used to compare the means for significantly different results. Significant differences in growth were obtained at (p<0.05) in waxy corn for the number of leaves, the height of the first cob, length of cob, and girth between the control and all treatments. However, there is no significant difference for the sweetness of waxy corn for all treatments. Mean total for growth parameters; the number of leaves, stem girth and height of the first cob from soil surfaces and mean total for yield parameters; cob girth, length of cob, fresh weight of cob, 100 grains weight and the number of kernels was significantly higher for all treatments of T2, T3 and T4 compared to control the treatment of T1. The study showed no significant difference in the sweetness of waxy corn with increasing potassium application, resulting in increased total soluble content. Similar studies for a different rate of organic fertilizers and soil analysis can be done to ascertain further the effects on growth, yield, and sweetness parameters of reddish waxy corn with selected soil properties.

Agroecology is relatively a new term for local community in Malaysia. For agroecology practices to be widely accepted require better understanding of what it is, what are the agroecological attributes, and what are those elements in agroecology. In general, agroecology has ten elements, and it appears none or impossible nearly for any agricultural practices to fully comply with all these elements, but perhaps a combo high number of elements at certain degree of trade-off among those elements would be a feasible approach. In this study, we revealed some of the published practices available in Malaysia, as an example. The intention of the review effort is to reveal where we are currently, and how to move forward. Four case studies are discussed. First, agroecology approaches for cereal crops revealed up to four elements of agroecology have been implemented in the plantation, but also some elements remain unexplored. Second, a comparison has been made between the paddy cultivation by agroecology with conventional cultivation. Agroecology method in paddy farm have shown to save cost, environmentally friendly, and generate produced with better health benefit over the conventional method. Third, the examples of agroecological practices in oil palm plantation displayed many impressive solutions in line with agroecology, but similar with cereal crop practices that it has a limited inclusion of agroecology elements. Some of the agroecology elements can be explored further for implementation in agriculture are resilience, human and social values, culture and food traditions, responsible governance, and circular and solidarity economy.

Soil water vapor movement carries mass of water and its bulk quantity in motion carries a specific amount of energy. The moment when water molecules obtain enough energy to release themselves from liquid surface, it involves phase transition from liquid to gas phase. The energy required for its release or freedom must be sourced from some energy source in the soil. The energy can come from the soil, water, or gas phase in the immediate surrounding. As such, the water phase transition into gas phase absorbs energy and causes temperature variation. Since vapor carries a significant amount of energy, its evaporation can cause a significant amount of temperature in the soil. Hence, studying vapor movement in soil and the factors affecting vapor movement is an important subject of concern. The current study is looking into factors that affect soil water vapor movement in the soil. The equation from Philip and de Vries was examined in the current study. We found that soil water vapor movement was not limited to factors affecting vapor phase, the vapor phase was in continuous interaction with other factors that affecting liquid water movement and heat flux in the soil.