Greenhouse experiments were carried out to study the effect of biochar and other organic amendment (Chicken Manure, CM; and City waste compost, CW) using on the growth and N fertilizer requirement of maize. The first experiment was carried out to study the effect of biochar application to maize growth, and then continued to study the residual effect of biochar. The second experiment was carried out to study the effect of biochar application on nitrogen fertilizer requirement. The results show that the first season of maize biomass of organic amendment of treated soils did not significantly different from no organic amendment. However, organic amendment improved soil fertility status, especially increasing C-organic, N, K and CEC. The biomass of the second season maize of biochar of treated soil was higher compared to the other treatments. The second experiment shows that biochar application decreased N fertilizer requirement. To produce 3.23 Mg ha -1 biomass, it required 90 kg ha -1 N for 15 Mg ha -1 CM biochar treated soil, and 160 kg ha -1 for the non treated soil.

A research was conducted to study the effect of nitrogen and potassium (NK) fertilizers and plant density on the growth and yield of taro (Colocasia esculenta (L.) Schott var. Antiquorum). The field experiment was carried out at Brawijaya University experimental field station located at Jatikerto, Malang, Indonesia. The experimental treatments consist of three plant density (18,000, 24,000 and 30,000 haG

Sonic bloom is a technology that combines high frequency sound waves and organic nutrients, intended for better plant growth to increase its productivity. This study aimed to determine the effect of sound wave frequency and drought stress on stomatal opening, nutrient uptake efficiency through leaf, and soybean yield. We designed the research as a split plot experiment. The main plot was sound wave frequency consisting of four levels (no frequency imposed, frequencies 2, 4 and 6 kHz. The sub-plot was three soil moisture contents (50,75, and 100% field capacity). We found that the interaction of frequency and soil moisture content affected the width of stomata at the age of 30,40 and 50 days after planting (dap), the efficiency of nitrogen uptake, phosphorus uptake and potassium uptake and the protein content of seeds. The width of stomatal opening at a frequency of 4 kHz in soil moisture 100% FC showed the highest value and was not significantly different from soil moisture 75% FC. There was a positive correlation between exposure to plants with a frequency of 4 kHz with stomatal opening, nutrient uptake and increased yield of soybean crops. The use of sonic bloom technology with plant exposure at a frequency of 4 kHz could increase drought tolerance to 75% soil moisture content. Soybean seed yield increased by 40.89% and seed protein content increased by 10.3%.

No abstract

In Wakatobi district nutmeg trees are generally cultivated in mixed planting with coconut. The research employed observation method where sample plants were determined purposively based on intersection of nutmeg and coconut tree crowns; 42 plots of pairs of nearest neighboring plants. In each plot of pair of plants, plant density of nutmeg and coconut was calculated (individually and in total), then microclimate components (solar radiation, temperature and relative humidity) and nutmeg plant characteristics (vegetative and prodution components) were measured. Research results showed that plant density of nutmeg (218 plants ha -1 ) had exceeded its optimum number of population, plant density of coconut 144 plants ha -1 with relative density ratio of 58:42% or nutmeg was more dominant than coconut. Transmitted radiation and temperature below the crown was decreasing, and in contrast, intercepted radiation and relative humidity increased in line with the increased plant density of nutmeg. This condition led to the decrease in sum of fruits, weight of mace, and weight of kernel of individual nutmeg tree. Coconut plant density had non-significant correlation and non-significantly contributed to microclimate and production components of nutmeg. This indicated that the tendency for decreased production of nutmeg is less affected by coconut trees, but more because of shading effect of nutmeg trees due to close distance among them. In other word, there occured intraspecific competition (nutmeg and nutmeg), and not interspecific (nutmeg and coconut). Therefore, coconut can be cultivated in mixed planting with nutmeg through appropriate plant spacing.