Short-Term Effect of In Situ Biochar Briquettes on Nitrogen Loss in Hybrid Rice Grown in an Agroforestry System for Three Years

Abstract. Suryanto P, Kurniasih B, Faridah E, Nurjanto HH, Rogomulyo R, Handayani S, Kastono D, Muttaqien AS, Alam T. 2020. Influence of furrow with organic material and Chromolaena odorata compost on upland rice productivity in an agroforestry system with Melaleuca cajuputi. Biodiversitas 21: 780-791. The main problems of rainfed areas for upland rice cultivation in agroforestry system with Melaleuca cajuputi (kayu putih) were limited to soil moisture availability and low fertility of the soil. The experiment was conducted from March to August 2018 in Menggoran Forest Resort, Playen Forest Section, Yogyakarta Forest Management District, Indonesia. The experiment was arranged in strip plot design with three blocks as replications. The vertical plots were rainwater harvesting technique (RHT) consist of without furrow (WF) and furrow with organic material (FWOM). The horizontal plot was Chromolaena odorata (siam weed) compost (SWC) applications consist of 0, 5, 10, and 15 tons ha-1. The data analyzed by ANCOVA, ANOVA, SEM, and stepwise regression. The results of the study informed that the FWOM with SWC of 10 tons ha-1 showed the highest yield of upland rice per hectare was 2.97 tons ha-1 and yields increased by 91.75% compared to the WF without SWC. The environmental variables that significantly affected the yield of upland rice were WUE and Tsoil. The growth variables that significantly affected the yield of upland rice were SDW, RSA, and RDW. The yield component that had a very significant affected on the yield of upland rice was NP.

Abstract. Suryanto P, Faridah E, Nurjanto HH, Supriyanta, Kastono D, Putra ETS, Handayani S, Dewi AK, Alam T. 2020. Influence of siam weed compost on soybean varieties in an agroforestry system with kayu putih (Melaleuca cajuputi). Biodiversitas 21: 3062-3069. Siam weed (Chromolaena odorata (L.) R.M.King & H.Rob.) has grown wild in many kayu putih (Melaleuca cajuputi Powell) forest can be utilized as compost for complementary of inorganic fertilizers in annual crops. The experiment was conducted during November-February 2020 in Menggoran Forest Resort, Playen Forest Section, Yogyakarta Forest Management District, Indonesia. The experiment was arranged in a randomized complete block design (RCBD) with three replications. The first factor was soybean varieties consisted of Anjasmoro, Dering I, and Grobogan. The second factor was siam weed compost (SWC) application consisted of 0, 5, 10, and 15 tons ha-1. The data were analyzed using Two-way ANOVA, ANCOVA, and stepwise regression. The SWC application of 10 tons ha-1 showed the highest yield of Anjasmoro, Dering I, and Grobogan were 1.42, 1.56, and 1.51 tons ha-1, respectively, or increased by118.46%, 102.60%, and 112.68%, respectively, compared to the without SWC application. The optimum dosage of SWC application for Anjasmoro, Dering I, and Grobogan were 13.05, 14.35, and 14.93 tons ha-1, respectively, with a maximum yield of 1.45, 1.59, and 1.52 tons ha-1, respectively. Soil quality and physiological parameters that had a significant influenced on the production of soybean varieties in agroforestry systems with M. cajuputi were SOM, K, LPR, TC, and PRO.

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.

Abstract. Taryono, Supriyanta, Wulandari RA, Nurmansyah, Ambarwati E, Arsana IGKD, Aristya VE, Purba AE, Aisya AW, Alam T. 2023. Selection of drought-tolerant rice genotypes under cajuput (Melaleuca cajuputi subsp. cajuputi) agroforestry system. Biodiversitas 24: 4791-4802. Rice production can be increased by expanding rice cultivation area on agroforestry land. However, planting rice in agroforestry system, which is generally rainfed, might cause drought stress and eventually can reduce rice yields. The study aimed to select rice genotypes under drought stress conditions in a rainfed agroforestry system with cajuput or kayu putih (Melaleuca cajuputi subsp. cajuputi Powell). Ten promising rice lines and four control cultivars were grown during the dry season from March-July 2022 at the Menggoran Forest Management Resort, Playen Forest Section, Yogyakarta Forest Management, Indonesia. The observation was conducted on drought stress tolerance (sensitivity and recovery), molecular identification, and yield of rice cultivars. The results showed that G5 was the genotype with drought tolerance and had the best recovery compared to the other promising rice lines and control cultivars. The molecular identification of the 14 rice genotypes using 20 SSR markers detected 108 alleles with a PIC value of 0.707. The G5, G4, and G9 had higher yields than the control cultivars. The BLUE showed that the yield of G5, G4, and G9 were 6.59, 5.93 and 5.50 tons ha-1, respectively, while for BLUP by 6.45, 5.87 and 5.43 tons ha-1, respectively. Furthermore, there were four clusters consisting of cluster 1 (G9), cluster 2 (G7), cluster 3 (G5 and Inpago 12), and cluster 4 (Inpari 42, G6, Inpari 30 Ciherang Sub 1, Situ Bagendit, G3, G4, G10, G2, G1, and G8). The findings of this study recommend G4, G5, and G9 as promising rice lines which tolerant to drought stress under M. cajuputi agroforestry system and can be utilized in future plant breeding programs.

Intercropping kayu putih ( Melaleuca cajuputi ) has more advantage than other tree crops, such as teak, pine or acacia due to the beneficial intercropping season length. Soybean was intercropped with kayu putih because soybean has higher commercial value than other field crops. The survey-based research was conducted during March until May, 2014 in Menggoran Forest Resort, Playen Forest Section, Yogyakarta Forest Management District. Stratified random sampling method was used during the research by stratifying the types of soil stratification (alfisol and vertisol), rainfall and declivity then was made into 7 land mapping unit (LMU) with map overlay technique. Agronomic characters of soybean were observed on 12 weeks after planting (wap) and the physiological data were observed during the maximum vegetative phase (8 wap). Agronomic and physiological characters of soybean in each LMU were grouped and statistically tested with analysis of variance (ANOVA) then continued with orthogonal contrasts (alpha 5%). The results showed that some characters of soybean planted in alfisol had higher value than in vertisol, especially on leaf area, photosynthetic rate, root and canopy weight, 100 grain weight and grain weight per plant. The agronomic and physiological characters of soybean which had significant effects on yield in the intercropping with kayu putih system were stomatal density, stomatal conductivity, photosynthetic rate, and leaf area. Soybean intercropped with kayu putih produced 1.007 tons/ha in alfisol and 0.996 tons/ha in vertisol. Soybean development in intercropping system of kayu putih can be conducted by using soybean varieties superior effort.

An experiment was conducted under laboratory conditions to investigate the effect of two systemic herbicides viz., pendimethalin and quizalofop, at their recommended field rates (1.0 kg and 50 g active ingredient ha(- 1), respectively) on the growth and activities of non-symbiotic N(2)-fixing bacteria in relation to mineralization and availability of nitrogen in a Typic Haplustept soil. Both the herbicides, either singly or in a combination, stimulated the growth and activities of N(2)-fixing bacteria resulting in higher mineralization and availability of nitrogen in soil. The single application of quizalofop increased the proliferation of aerobic non-symbiotic N(2)-fixing bacteria to the highest extent while that of pendimethalin exerted maximum stimulation to their N(2)-fixing capacity in soil. Both the herbicides, either alone or in a combination, did not have any significant difference in the stimulation of total nitrogen content and availability of exchangeable NH(4)(+) while the solubility of NO(3)(-) was highly manifested when the herbicides were applied separately in soil.

Soil Development and Nitrogen Turnover in Montane Rainforest Soils on Hawai'i

To effectively understand the availability of soil nitrogen and assist in soil nitrogen control at the regional scale, it is essential to understand the accurate spatial distribution patterns of the three soil nitrogen parameters [i.e., total nitrogen (TN), available nitrogen (AN) and nitrogen availability ratio (NAR)] and explore the spatially varying influences of major impact factors on soil AN. Land use affects the spatial distributions of soil TN, AN and NAR (i.e., AN/TN). To explore the effects of different land use types and improve mapping accuracy, residual kriging with land use information and ordinary kriging (without land use information) were compared based on the sample data of soil TN and AN in Hanchuan county, China. A local regression technique, geographically weighted regression (GWR), was adopted to explore the varying relationships between soil AN and its major impact factors in soil (i.e., soil TN and soil pH), due to the advantages of GWR over the traditional ordinary least squares regression (OLS) model. The results showed that (1) land use types as auxiliary information obviously improved the prediction accuracies of the three soil nitrogen parameters; (2) GWR performed much better than OLS in terms of fitting accuracy; and (3) GWR effectively revealed the spatially varying influences of the impact factors on soil AN, which were ignored by OLS. Based on the results, suggestions for soil nitrogen control measures in different subareas were proposed.

Abstract. Alam T, Suryanto P, Supriyanta, Basunanda P, Wulandari RA, Kastono D, Widyawan MH, Nurmansyah, Taryono. 2021. Rice cultivar selection in an agroforestry system through GGE-biplot and EBLUP. Biodiversitas 22: 4750-4757. Genotype-by-environment interaction (GEI) causes differences in the productivity of rice cultivars in agroforestry systems. For this reason, the stability of rice cultivars is an important aspect that should be considered before a cultivar is recommended to farmers. Superior genotypes and ideal environments are commonly identified using two statistical models, namely, genotype–genotype-by-environment biplot (GGE-biplot) and empirical best linear unbiased prediction (EBLUP). In this study, 15 rice cultivars were evaluated in terms of their productivity and stability in three soil types (Lithic Haplusterts, Ustic Epiaquerts, and Vertic Haplustalfs) in an agroforestry system with kayu putih (Melaleuca cajuputi) in 2019 and 2020 at the Menggoran Forest Resort, Playen Forest Section, Yogyakarta Forest Management District, Indonesia. The cultivars were treated as random effects to select and obtain the EBLUP of the best cultivars in each soil type. The EBLUP revealed that Situ Patenggang showed the highest yields of 4.887 and 5.456 tons ha?1 in Lithic Haplusterts and Vertic Haplustalfs, respectively. GM 28 exhibited the highest yield of 6.492 tons ha?1 in Ustic Epiaquerts. Ciherang, GM 2, GM 8, GM 11, GM 28, Inpari 6 Jete, Inpari 33, IR-64, and Way Apo Buru were classified as stable and fairly stable cultivars, whereas the other cultivars were unstable. Therefore, rice cultivars with high yields in specific soil types should be selected.

Intensive irrigated rice-wheat crop systems have caused serious soil depletion and nitrogen loss in the Tai Lake region of China. A possible solution is the incorporation of legumes in rice because legumes are a source of nitrogen. There is actually little knowledge on the impact of legumes on rotation, soil fertility, and nitrogen loss. Therefore, we studied the effect of five rice-based rotations, including rice-wheat, rice-rape, rice-fallow, rice-bean, and rice-vetch, on soil nitrogen, rice yield, and runoff loss. A field experiment was conducted in the Tai Lake region from 2009 to 2012. Crop residues from rape, bean, and vetch were used to partially replace chemical fertilizer in rice. Results show that replacing 9.5–21.4 % of mineral nitrogen fertilizer by residues maintained rice yields of rice-rape, rice-bean, and rice-vetch rotations, compared to the rice-wheat reference. Moreover, using legumes as a winter crop in rice-bean and rice-vetch combinations increased rice grain yield over 5 %, and increased rice residue nitrogen content by 9.7–20.5 %. Nitrogen runoff decreased 30–60 % in rice-rape, rice-bean, and rice-vetch compared with rice-wheat. Soil mineral nitrogen and microbial biomass nitrogen content were also improved by application of leguminous residues.

Yuan Longping, a great world hunger fighter

Irrigation and nitrogen fertilizer application are two important factors affecting yield and nitrogen loss in rice fields; however, the interaction effects of different irrigation schedules and combined management of nitrogen fertilizer application on yield and nitrogen loss in rice fields remain unknown. Therefore, we collected 327 sets of data on rice yield and 437 sets of data on nitrogen loss in rice fields from 2000 to 2021 and investigated the effects of different water-saving irrigation schedules, nitrogen application levels, and water–nitrogen couplings on rice yield, nitrogen use efficiency, and nitrogen loss (N2O emissions, nitrogen runoff, nitrogen leaching, and ammonia volatilization) by meta-analysis using conventional flooding irrigation and no nitrogen treatment as controls. The results showed that alternate wet and dry irrigation and controlled irrigation had increasing effects on rice yield. Alternate wet and dry irrigation had a significant yield-increasing effect (average 2.57% increase) and dry cultivation significantly reduced rice yield with an average 21.25% yield reduction. Water-saving irrigation reduces nitrogen runoff and leaching losses from rice fields but increases N2O emissions, and alternate wet and dry irrigation has a significant effect on increasing N2O emissions, with an average increase of 67.77%. Most water-saving irrigation can increase nitrogen use efficiency. Among water-saving irrigation methods, the effect of controlled irrigation on increasing nitrogen use efficiency is 1.06%. Rice yield and nitrogen use efficiency both showed a trend of increasing then decreasing with nitrogen fertilizer application, and nitrogen loss gradually increased with the amount of nitrogen fertilizer input. Water–nitrogen coupling management can significantly reduce nitrogen loss in rice fields while saving water and increasing yield. Based on the analysis of the data in this study, when the irrigation amount was 300~350 mm and the nitrogen application amount was 200~250 kg/ha, the rice yield and nitrogen fertilizer use efficiency were at a high level, which corresponded to the irrigation schedule of controlled irrigation or alternating wet and dry irrigation in the literature. However, different rice-growing areas are affected by rainfall and land capability, etc. Further optimization and correction of the adapted water and fertilizer management system for paddy fields are needed. The optimal water–nitrogen pattern of this study can achieve high rice yield and reduce nitrogen loss.

Conventional agriculture is the dominant contributor to negative environmental impacts such as the growth in global greenhouse gas (GHG) emissions, and the challenges are likely to increase with the increasing global food demand as well as the agricultural expansion. Agroforestry is a sustainable management practice with strong potential to provide ecosystem services and environmental benefits through increasing carbon sequestration, nutrient availability, water use efficiency and biodiversity, and reducing soil erosion and nitrogen losses. Therefore, the establishment of agroforestry practices offers an opportunity to reduce GHG emissions. Previous studies have showed the effects of agroforestry on soil nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) fluxes in many parts of the world. In temperate Europe, the information on the GHG mitigation potential of agroforestry compared to cropland monoculture is still unclear. The present thesis consists of two studies, which was designed to explore whether the conversion of cropland monoculture to agroforestry systems reduces trace gases N2O, CO2, and CH4 emissions from the soil. The study was carried out at three sites varied with soil types in Germany. Each site had adjacent alley cropping agroforestry and cropland monoculture systems and the trees in agroforestry system were planted 1 to 11 years prior to this research. We measured soil N2O, CO2, and CH4 fluxes monthly using vented static chambers at the three sites from March 2018 to January 2020. On each day of gas sampling, soil temperature, water-filled pore space and extractable mineral nitrogen (N) were measured in the top 5 cm. The objective of our first study was to quantify the spatial-temporal dynamics of soil N2O fluxes from cropland agroforestry and monoculture systems, following different crop rotations and fertilization rates. The pattern of soil N2O fluxes were predominantly controlled by soil mineral N in both agroforestry and monoculture systems. The positive relationship between water-filled pore space with soil N2O fluxes during the cropping seasons, indicating soil moisture acts as a limiting factor under N-sufficient conditions. The entire agroforestry systems tended to reduce soil N2O emissions by 9% to 56% compared to monocultures, during the corn phase of the rotation that had typically high fertilization rates. The lowest soil N2O emissions in the unfertilized tree rows (occupied 20% of the agroforestry area) represent a potential for mitigating N2O emissions from croplands. The objective of our second study was to investigate the changes in soil CO2 and CH4 fluxes after conversion from cropland monoculture to alley cropping agroforestry systems. Our results showed that seasonal variations of soil CO2 and CH4 fluxes were strongly regulated by soil temperature and moisture, and the spatial variations were mainly controlled by texture. The establishment of agroforestry systems had no effect on reducing soil CO2 emissions, possibly because there was no significant difference in soil temperature between management systems. Annual soil CH4 uptake in the agroforestry systems was increased by up to 300% compared to monocultures, which may be related to the regulation of trees on soil moisture in agroforestry systems. The present research provides the first insight into the systematic comparison of soil N2O, CO2 and CH4 fluxes from cropland agroforestry and monoculture systems, and it provides a unique dataset for estimating the net balance of carbon emissions after conversion of cropland monoculture to alley cropping agroforestry system in temperate regions. Although soil CO2 emissions showed no differences between management systems, the total annual soil emissions of non-CO2 GHG from agroforestry systems were reduced by 0.22 Mg CO2 eq ha-1 compared to the monocultures. Considering the driving function of soil moisture and mineral N on soil GHG fluxes from cropland agroforestry and monoculture systems, our findings suggest that improved system management (e.g. optimal adjustments of the areal coverages between tree and crop rows) and optimized fertilizer input will enhance the potential of cropland agroforestry for mitigating N2O emissions and increasing CH4 uptake and C sequestration in the long run.

The hybrid rice technology could be considered a boon for food security for many in South and Southeast Asia to increase rice productivity. In China, the birthplace of hybrid rice (HR), the diffusion of hybrid rice started in 1976. About 28% rice-growing area in China is planted with hybrid rice. However, the proportion of HR area in China has been declining in recent years, and farmers in surrounding countries are reluctant to adopt it because of high seed costs, farm management practices, and quality issues. Most previous research on the evaluation of hybrid rice variety on yield does not control input level. This study uses the endogenous switching regression method to analyze the impacts of HR adoption on rice yield and net rice income. The study uses plot- and household-level data from four southern provinces of China. Findings show a significant effect of HR adoption on rice yields. On the same HR plots, compared to CR adopters, rice yield increases by 4.86% for HR adopters. Rice yield would increase by 4.72% if the HR variety was adopted on the same conventional rice (CR) plots. Additionally, findings show a significant effect of HR adoption on net rice incomes. On the same HR plots, compared to CR adopters, net rice income decreases by 43.61% for HR adopters. Similarly, net rice income would reduce by 10.95% if the HR variety was adopted on the same CR plots. Thus, adopting HR increases rice productivity, but Chinese farming households that adopted CR would not benefit from adopting HR. Policymakers can formulate a systematic and comprehensive rice breeding plan to guide the simultaneous development of rice variety yield and quality improvement. Additionally, policymakers, in conjunction with private companies, could enact policies to reduce the cost of hybrid rice seed or improve the production efficiency of HR. For example, they could incentivize the development of HR varieties suitable for direct seeding and seed-saving sowing methods (rice trans-planter).

Field experiment was conducted for two consecutive years from kharif 2015 and summer 2017at research farm of Division of Agronomy, Skuast Jammu to study the effect of differential substitution of nutrients through organics on yield, nitrogen uptake and balance sheet of nitrogen of four crops basmati rice (1st crop) - knolkhol (2nd crop) - knolkhol (3rd crop) - green gram (4th crop) in cropping sequence for two years in Irrigated subtropical conditions of Jammu and Kashmir. The result of two year studied showed that significantly highest yield of all the four crops in two crop cycles in the rice based cropping system viz., basmati rice, knolkhol-1, knolkhol-2 and green gram were recorded with 100 % recommended dose of fertilizer which was found statistically at par with yields recorded with treatments 75 % NPK +25 % N through vermicompost and Fym (1:1),25% yearly replacement of RDF through vermicompost and Fym (1:1) on N basis,75% NPK+25% N through vermicompost,25 % yearly replacement of RDF through vermicompost on N basis,75 % NPK+ 25 % N through Fym and 25% yearly replacement of RDF through Fym on N basis. Further, highest mean total nitrogen uptake (544.95 kg/ha) in rice based cropping system were recorded with treatment 25% yearly replacement of RDF through Fym on N basis followed by treatment 75 % NPK+ 25 % N through Fym (541.29 kg/ha) whereas highest build-up of available nitrogen in soil after two crop cycles (8.79 kg/ha) was recorded with treatment 100 % N through Farmyard manure followed by treatment 100% N through Vermicompost whereas lowest build-up of available nitrogen (4.53 kg/ha) in soil was recorded with treatment 100 % Recommended dose of fertilizer in rice based cropping system.