Food waste is a vast issue global, including in Malaysia. Food waste brings negative impacts, including increasing food production costs, impact on human health, and environmental degradation. Malaysian’s animal- and plant-based diet preferences affected the desired food waste decomposition method as most of the methods only allow plant-based material to be utilized as food waste compost. The objectives of this study were to understand Malaysians' awareness of food waste behaviour and the food waste component for the decomposition. Malaysians usually produce more plant-based food waste than animal-based food waste. Most Malaysians have a high awareness of causes and impact of food waste, but they lack action on food waste reduction. Bio-compost is believed to be the most effective method to manage food waste, and most of them were willing to have it at home. However, some of them are unwilling to have a compost pile at home because there is no time to take care of it.

Understanding carbon mineralization dynamics of organic amendments is essential to restore degraded lands. This study focused on the restoration potentials of tea-growing soils using organic materials available in tea ecosystems. The Selangor-Briah soil series association (Typic Endoaquepts) consisted of a high- (soil A) and a low-carbon (soil B) soils were incubated with different organic materials and released carbon dioxide (CO₂) measured. Two kinetic models were applied to depict the mineralization process. Soil health parameters including microbial biomass carbon and nitrogen, dehydrogenase and catalase activities were determined to assess the restoration potentials. The parallel first-order kinetic model fitted well for all amendments. Gliricidia markedly enhanced the net cumulative CO₂ flux in both soils. Charged biochar, tea waste and Gliricidia improved the microbial biomass carbon by 79–84% in soil A and 82–93% in soil B, respectively. Microbial quotients and biomass nitrogen were increased over 50 and 70% in amended soils, respectively. Dehydrogenase activity was significantly accelerated over 80% by compost, charged biochar and tea waste. Charged biochar remarkably increased the soil catalase activity by 141%. Microbial biomass, dehydrogenase and catalase activities, and cumulative CO₂ flux were positively correlated (r > 0.452) with one another. The studied amendments showed greater potential in improving the soil quality, while charged biochar, raw biochar and compost enrich the soil recalcitrant C pool ensuring the soil health in long term. Even though biochar sequesters carbon, it has to be charged with nutrients to achieve the soil restoration goals.

This study is a comparison of the litterfall, litter decomposition, soil macrofauna, and nutrient contents in rubber monoculture and rubber-based agroforestry plantations. The three intra-couple differences examined are rubber with pakliang (RP) compared with rubber monoculture (RMP), rubber with timber (RT) compared with rubber monoculture (RMT) and rubber with fruit (RF) compared with rubber monoculture (RMF). Rubber plantation systems were selected at 3 plantations located in nearest pairs at 18 plantations in total. Data collected included litterfall at monthly intervals from October 2016 to April 2017, as well as decomposition conditions for assessment at the end of the experimental trials. Soil samples examined the species and number of macrofaunal and decomposition measurements of mesofauna by using Lamina bait scale to analyze nutrient content. Results showed the litterfall of leaves, twinges, and fruits in rubber monoculture and rubber-based agroforestry plantations were not significant between pair comparisons. This showed leaves fell at a high incidence. However, RT experienced a higher trend in litterfall. Decomposing litterfall was also not significant between pair comparisons, but when compared by associated plant species found that RT trends were more likely to experience higher decomposition rates and the litter index was higher as well. Macrofauna in the topsoil (0-5 cm) and subsoil (5-10 cm) were not significant. The composition of mesofauna was found at high decomposition rates in RF, RP, and RT. Organic matter and nutrient contents were not significant in both soil layers. Our data emphasizes that rubber-based agroforestry plantations help regulate C and nutrient cycles, implying that external input fertilizer management requirements for rubber farmers decreased.

In Malaysia, the main constraints of rice yield and productivity are infertile soils and poor management practices because these soils are characterized by low pH, low nutrient availability, low organic matter, and high exchangeable Al and Fe ions, due to high rainfall and hot temperatures. Thus, an incubation study was conducted to determine the optimum amount of calcium silicate (HmbG brand) to improve the soil pH, electrical conductivity (EC), exchangeable Al, available P, and cation exchange capacity (CEC) of a paddy soil in Sabah, Malaysia. The Kelawat series (Typic Dystrudept) soil was incubated with calcium silicate at the application rates of 0 (T1), 1 (T2), 2 (T3), and 3 t ha⁻¹ (T4) using a Completely Randomized Design (CRD) in triplicates for 30, 60, 90, and 120 days. The calcium silicate used significantly improved soil pH because of the release of SiO₄⁴⁻ and Ca²⁺ ions, which neutralized and immobilized H⁺ ions. Furthermore, the neutralizing effects of the amendment impeded Al hydrolysis by up to 57.4% and this resulted in an increase in the available P in the soil by 31.26% to 50.64%. The increased availability of P in the soil was also due to the high affinity of SiO₄⁴⁻ to desorb P from soil minerals and it is believed that SiO₄⁴⁻ can temporarily adsorb exchangeable base cations such as K⁺, Ca²⁺, Mg²⁺, and Na⁺. Moreover, applying calcium silicate at 3 t ha⁻¹ improved soil CEC by up to 54.84% compared to that of untreated soils (T1) because of increased pH and the number of negatively charged sites. The most suitable application rate of the calcium silicate was found to be 3 t ha⁻¹ (T4). These findings suggest that calcium silicate can improve soil productivity and agronomic efficiency in rice farming. Greenhouse and field trials are necessary to ascertain the effects of the recommended treatments of this incubation study on soil productivity, rice growth, and yield.

Phosphorus (P) enrichment of soil due to the intensification of P fertilizer usage in crop production has resulted in eutrophication and serious economic consequences. Further, rapidly decreasing P reserves have renewed interest in improving more sustainable soil P management through monitoring diverse soil P reactions in contrasting soils. Therefore, the study was conducted to (i) characterize P sorption and desorption capacities related to soil properties and (ii) determine the added P availability and distribution among the different pools of P over the period concerning P sorption capacity of the soils. Three soils, namely Ultisols, Entisols, and Inceptisols, were equilibrated with a series of P concentrations to study P sorption–desorption using Langmuir isotherms. These soils were subjected to a sequential extraction procedure to study fractions in different pools after incubating with added P for 120 days. Maximum P sorption for Ultisols, Entisols, and Inceptisols were 1,428.6, 1,666.7, and 3,333.3 mg kg⁻¹ soil, respectively. Phosphorus desorption by Ultisol was about 1.7- and 4.2-fold higher than Entisols and Inceptisols. The maximum P sorption showed a negative and significant correlation with soil pH (r = −0.88), whereas P des % has a significant and positive correlation (r = 0.98). Exchangeable Al, Al-ox, Al-cD, and Fe-ox showed a significant positive correlation with maximum P sorption and a negative correlation with P des %. During incubation, 93.3% of added P became non-extractable in Inceptisols, and in contrast only 64.3% for Ultisols. A greater increase in labile NaHCO₃-P fraction was found in Ultisols from 66.96 to 135.6 mg/kg at the end of the incubation. Accordingly, the soils with lower sorption capacity consist of more labile P pools, which indicates a higher risk of the loss of P from the soil.

A 45-day incubation and leaching experiments was conducted to determine the effect of different rates (0, 1, 2, 3, and 5 t ha⁻¹) of enriched empty fruit bunches biochar (EEFB) and inorganic fertilizer (91 kg ha⁻¹ triple superphosphate—TSP) on the availability and leaching losses of phosphorus from sandy soil (tin tailing soil). The treatments rates for the study were designated as T1—without fertilizer (control), T2—inorganic fertilizer treatment using TSP and T3, T4, T5, and T6, which refers to EEFB rate of 1, 2, 3, and 5 t ha^−1, respectively. The enriched biochar was prepared by shaking biochar with chicken manure extract for 24 h. The addition of EEFB to the soils was found to increase pH of the soil compared to control and inorganic fertilizer treatment. After 45 days of incubation, the percentage increase in available P recorded in EEFB treatments were 1.6, 2.9, 2.8, and 4.1%, whereas for control treatment and inorganic fertilizer treatment, the available phosphorus was found to reduce by 10% and 83%, respectively. Loss of phosphorus via leaching in the soil was higher in EEFB treatments compared to control. However, the highest phosphorus leaching among all treatments in this study was recorded in inorganic fertilizer treatments. From the study, it was observed that biochar can be used to recapture phosphorus from chicken manure extract for transport to the soil, thereby reducing problems associated with chicken manure application.