Many crops are colonized with arbuscular mycorrhizae fungi (AMF), which can efficiently absorb nutrient from the soil and induce plant immunity. The purpose of this study was to investigate the effects of AMF and rock phosphate (P) fertilizer applications on available P and some secondary plant metabolite in robusta coffee. The experiments were laid out in a 3 × 4 factorial randomized complete block design with AMF inoculants (control, Glomus intraradices LU3, Glomus sp. 2TS5) and rock phosphate fertilizer levels (0, 100, 200, and 400 g plant⁻¹). Parameters measured root colonization percentage, available P in soil, total P in leaf, salicylic acid and phenolic compounds in leaves. The results showed that there was significant interaction between AMF and P in root colonization density, available P in soil, total P in leaves, and salicylic acid content. AMF (both Glomus intraradices and Glomus sp.) improved root colonization density (64–65%), available P in soil (30–50%), total P in leaves (37–40%), salicylic acid content (8–19%), and phenolic compounds in leaves (53–74%) compared to the control. Also, higher P at 400 g plant⁻¹ increased root colonization density, available P in soil, total P accumulation in leaves, and salicylic acid. Therefore, AMF and rock P potentially represent an alternative way to promoting P uptake and plant immune in coffee.

The purpose of this research was study the rate and application method of calcium silicate (Ca2SiO4) fertilizer appropriated for pepper seedling production. This study was divided into two experiments. Experiment 1, the effect of Ca2SiO4 fertilizer application in pepper seedling by mixed in growing media was arranged in 2x6 factorials in Completely Randomized Design (CRD) with 4 replications. Factor A was seed preparation methods (seed primed with Ca2SiO4 fertilizer at a rate 2 g L-1 and non-seed primed) and factor B was application rates of Ca2SiO4 fertilizer at 0, 30, 60, 120, 240 and 480 kg ha-1. Experiment 2, the effect of Ca2SiO4 fertilizer application in pepper seedling by foliar method was arranged in 2x6 factorials in CRD with 4 replications. Factor A was seed preparation methods and factor B was application rates of Ca2SiO4 fertilizer at 0, 2, 4, 6, 8 and 10 g L-1. All experiments data were collected such as plant growth and total silicon content in plant at 28 days after sowing (DAS). From experiment 1, the results showed that seed primed with Ca2SiO4 fertilizer application at a rate 120 kg ha-1 gave the good plant growth and total silicon in plant. Experiment 2, the results showed that seed primed with Ca2SiO4 fertilizer application at a rate 2 g L-1 gave the highest of plant growth and total silicon in plant. To conclude, Ca2SiO4 fertilizer application can be employed for enhancing plant growth of pepper seedling and increasing silicon content in plant.

The objective of this study was to efficiency determined of mycorrhizal fungi with different phosphate fertilizer application on phosphate solubilizing and soil properties of grapes orchard. The treatments were arranged in 2x5 factorials in Randomized Complete Block Design (RCBD) with 5 replications. Factor 1: two levels of mycorrhizal fungi were non-inoculation and inoculation. Factor 2: five levels of phosphate fertilizer application were 0, 27.17, 54.34, 81.52 and 108.69 g plant-1 by soil analysis recommendation. The collected data was spore number, root colonization density, phosphatases activity of mycorrhizal fungi, available phosphorus (P) in soil, soil pH and phosphorus in leaf. The results showed that the inoculation of mycorrhizal fungi increased spore number, root colonization density, phosphatases activity of mycorrhizal fungi, available P in soil and P in leaf compared with the non-inoculated. While, phosphate fertilizer at a rate 54.34 g plant-1 increased spore number, root colonization density, phosphatases activity of mycorrhizal fungi, available P in soil and P in leaf. Mycorrhizal fungi combination with 54.34 g plant-1 of phosphate fertilizer increased spore number, root colonization density, phosphatases activity and available P in soil.

The production of 25-7-7 analysis grade of suspension fertilizer processed by Luxen’s Method was investigated for some physical properties changes during various storage periods. The solid instead of liquid raw materials were used in the production. The experiment was designed in CRD consisting of six storage treatments; 0, 7, 15, 30, 90 and 180 days with 4 replicates . The total urea was provided for Urea 1 being fed in clear liquid mixed solution stage and Urea 2 being fed in suspended solution stage. The process was to add Urea 1, xanthan gum, KCl, MKP, and Urea 2, respectively, into the cylindrical glass bottle which was mounted to the adjustable speeds of mixer and presented water. The resulting 25-7-7 analysis grade of suspension fertilizers were stored undisturbed at normal room temperature for various storage periods and its physical properties were analyzed periodically. The analysis of variance was performed using R statistical program. The result showed that pH of the suspension fertilizer ranged between 5.5-5.6 and specific gravity ranged 1.249-1.274 during all storage periods and there was nosignificant difference . The fertilizer viscosity increased as the storage times increased. The stability and the pour-ability were significantly decreased as the storage times increased . However, after six months, both stability and pour-ability were found to be above acceptable level. The changes in salting-out were found to be no significant difference among various storage periods. The result showed that the suspension fertilizers which were produced by Luxen’s method could maintain their appropriate physical properties during six months of storage times.

It is well known that submerged soils emit high levels of methane (CH₄) due to oxygen deprivation and free iron oxide causing a quick reduction. However, there are other soil properties that control the reduction processes in soil, especially the amount of soil organic carbon (SOC). This study aimed to investigate the major factors controlling CH₄ production potential (CH₄PP) in Thai paddy fields. Two provinces, Ayutthaya, a clay soil region, and Khonkaen, a sandy soil region, were selected to represent a wide range of soil textures. Soil characteristic analysis pre- and post-incubation, and weekly gas detection in an incubation experiment over two months, was conducted. Stepwise multiple regression analysis was employed to analyze major soil factors controlling CH₄PP. For the regional prediction of CH₄PP, a map dataset of Ayutthaya and Khonkaen by the Land Development Department, Thailand, and a soil texture map (with intersected point data using the soil property map in ArcGIS) by OpenLandMap, were used. CH₄PP was correlated with 1:10 pH, Fe²⁺, and water-soluble organic carbon (WSOC) measured after incubation. Although CH₄PP showed no significant correlation with any soil properties measured before incubation, CH₄PP was correlated with SOC, 1:10 electrical conductivity (EC), exchangeable ammonium (ExNH₄), and sand content. It was thought that SOC and ExNH₄ were related to organic matter decomposition, 1:10 EC was related to SO₄²⁻ reduction and sand content was related to free oxides. Predicted regional CH₄PP was similar in Ayutthaya and Khonkaen, although SOC, ExNH₄ and 1:10 EC was higher, and sand content was lower in Ayutthaya than in Khonkaen. In both regions, the distribution of CH₄PP corresponded to SOC, and CH₄PP was lower with lower sand content and higher 1:10 EC. In clayey Ayutthaya, higher CH₄PP was observed in the area with higher ExNH₄. This indicates that soil properties other than soil texture and SOC influence CH₄PP in the paddy fields in Thailand.