Abstract. Suryanto P, Taryono, Supriyanta, Kastono D, Putra ETS, Widyawan MH, Alam T. 2020. Assessment of soil quality parameters and yield of rice cultivars in Melaleuca cajuputi agroforestry system. Biodiversitas 21: 3463-3470.  Interactions between rice cultivars and soil quality parameters rises problems in the attempt of increasing rice yield. The objective of this study was to assess soil quality parameters that affect the yield of 15 rice cultivars in an agroforestry system of ‘kayu putih’ (Melaleuca cajuputi) situated in Menggoran forest, Yogyakarta, Indonesia which have three soil types namely Lithic Haplusterts, Ustic Epiaquerts, and Vertic Haplustalfs. The observation was conducted on 21 soil quality parameters and yield of rice cultivars. The data were analyzed by using ANOVA, factor analysis, and stepwise regression. The highest yield of rice per hectare was attained by GM 28 in Ustic Epiaquerts with 6.493 tons ha-1, while Situ Patenggang and GM 28 in Vertic Haplustalfs as high as5.549 and 5.401 tons ha-1, respectively, and Situ Patenggang in Lithic Haplusterts as high as 4.893 tons ha-1. Soil quality parameters that had significant effect on the yield of rice cultivars were Clay, SMC, pH, SOC, N, Mg, Fe, Fg, and Bae. We suggested that rice cultivars recommendations for Lithic Haplusterts, Ustic Epiaquerts, and Vertic Haplustalfs are Situ Patenggang, Situ Patenggang or GM 28, and GM 28, respectively, in addition to fertilization based on limiting factors of each rice cultivars.

Background: Nutrient briquette and biochar are used to reduce nitrogen loss and improve soil fertility. This study aimed to evaluate the interaction of biochar briquette with ammonium sulfate fertilizer for controlled nitrogen loss in soybean intercropping with Melaleuca cajuputi.Methods: The study was conducted in the wet season from November to February 2020 at Menggoran Forest Resort, Playen Forest Section, Yogyakarta Forest Management District, Indonesia. The experiment was using a randomized complete block design factorial with three blocks as the response surface methodology. The treatments included different levels of biochar briquette from Melaleuca cajuputi waste (0, 2 and 4 grain plant-1 or 0, 5 and 10 tons ha-1) and nitrogen fertilizer supplied by ammonium sulfate (0, 50 and 100 kg ha-1) as independent variables. The observation parameters were nitrate reductase activity (NRA), total chlorophyll (TC), leaf photosynthesis rate (LPR), nitrogen loss (NL), nitrogen use efficiency (NUE) and seed yield (SY).Result: The optimum values of 3.70 grain plant-1 or 9.25 tons ha-1 biochar briquette with 76.31 kg ha-1 ammonium sulfate fertilizer decreased NL by 38.25% and increased SY by 13.02% compared with single ammonium sulfate fertilizer.

Background: The main problem in nitrogen fertilization for crop cultivated is the very low efficiency due to the leaching process. The purpose of this study was to the determination of the optimum levels of biochar amendment made from Melaleuca cajuputi biochar (MCB) and urea fertilizer (UF) for nitrogen use efficiency in upland rice under M. cajuputi stands.Methods: The study was conducted during dry season within March to June 2019 in Menggoran Forest Resort, Playen Forest Section, Yogyakarta Forest Management District, Indonesia. The experimental design was laid out in a randomized complete block design factorial with three replications as the response surface methodology (RSM). The treatments consisted of MCB levels (0, 5, 10, 15 tons ha-1) and UF levels (0, 100, 200, 300 kg ha-1) as independent variables. The observation parameters were nitrate reductase activity (NRA), total chlorophyll (TC), leaf photosynthesis rate (LPR), nitrogen loss (NL), nitrogen use efficiency (NUE) and seed yield (SY). The data was analyzed using RSM approach and ridge regression.Result: The optimizing applications of 11.14 tons ha-1 of MCB and 281.13 kg ha-1 of UF resulted in NUE and SY by 2.14 kg grain kg Nfertilizer-1 and 5.83 tons ha-1 or increased by 19.07% and 13.02%, compared to a single application of UF by 300 kg ha-1.

Abstract. Widyawan MB, Hasanah A, Taryono, Alam T, Sayekti RS, Pramana AAC, Wulandari RA. 2020. Multivariate analysis unravels genetic diversity and relationship between agronomic traits, protein, and dietary fiber in yardlong bean (Vigna unguiculata subsp. sesquipedalis Verdc.). Biodiversitas 21: 5662-5671. Yardlong bean (Vigna unguiculata subsp. sesquipedalis Verdc.) is a vegetable legume that possesses the highest amount of protein and total dietary fiber (TDF) content among other vegetables. However, protein and TDF content diversity are found among yardlong bean genotypes. Genetic improvement to produce cultivars with high yield and improved nutritional content is required. This study aimed to analyze genetic diversity and identify the relationship between important agronomic traits from 21 yardlong bean genotypes assessed by multivariate statistical analysis. The experiment was arranged in alpha design with three replicates, each consist of six blocks. Six pod-related important agronomic traits, protein, and TDF content were observed in this study. Total pod weight, pod weight, and pod length were found to be negatively correlated with protein and TDF content based on correlation and principal component analysis (PCA). Although negatively correlated, several variables possess a large and positive direct effect on protein and TDF content, such as the number of pod, pod weight, and days to flower. D2 analysis and Tocher’s method classify genotypes used in this study into five clusters with diverse traits value. Information from this study laid a foundation for the improvement of important agronomic traits as well as nutritional content in yardlong bean.

Kayu putih (Melaleuca cajuputi) waste has the potential via in situ biochar briquettes to overcome the low availability of nitrogen in soil. This study evaluated the short-term effects of in situ biochar briquettes on nitrogen loss reduction and determined an optimum scenario for hybrid rice grown in an agroforestry system among kayu putih stands. This three-year experiment (2019–2021) was conducted using a randomised complete block design factorial with three blocks as replications. The treatments included biochar briquettes made from kayu putih waste (0-, 2-, 4-, and 6-grain plant−1 or 0, 5, 10, and 15 tonnes ha−1) and urea fertiliser (0, 100, 200, and 300 kg ha−1). The results demonstrated that the eco–environmental scenario was the most efficient strategy that improved the soil quality, the physiological characteristics, and the yield of the hybrid rice with the optimum application of the biochar briquettes at 5.54-grain plant−1 and the urea fertiliser at 230.08 kg ha−1. This alternative approach illustrated a reduction in both the usage of urea fertiliser and the loss of nitrogen by 23.31% and 26.28%, respectively, while increasing the yield of the hybrid rice by 24.73%, as compared to a single application of 300 kg urea ha−1 without biochar briquettes.