Application Of Rice Straw Compost Research Articles

Application of Rice Straw Compost and NPK Fertilizer to Increase The Growth of Kale Land (Ipomoea reptans poir)

Kale land can grow well in various environmental conditions. Fertilization is one way that can be done to increase the growth of Ipomoea reptans poir using both organic and inorganic fertilizers. Research on the application of rice straw compost and NPK fertilizer to increase the size of stems and leaves of Ipomoea reptans poir has been completed in 2023. This research aims to analyze: (1) the effectiveness of using NPK fertilizer on the size of stems and leaves of Ipomoea reptans poir, 2) the effectiveness of using rice straw compost on the size of stems and leaves of Ipomoea reptans poir, (3) the effectiveness of the combination of using rice straw compost and NPK fertilizer on the size of stems and leaves of Ipomoea reptans poir. Two factorial design was applied in this research. The results were obtained: (1) the application of rice straw compost was significantly effective in increasing stem height, leaf length and leaf width but could not increase the rate of increase in the number of kale land leaves, (2) NPK fertilizer treatment had a real effect on increasing the overall growth parameters observed, (3) ) the combined application of rice straw compost and NPK fertilizer did not have a significant effect on leaf width, number of leaves, leaf length and stem height of kale land.

Fusing Genotype and Soil Organic/Inorganic Amendment to Improve Saline-sodic Properties and Rice Productivity

AbstractSoil salinization and sodification have become a considerable threat to sustainable crop production for food security. The efficient biological practice in rice cropping systems, besides modulating saline-sodic soil properties using different amendments, is a necessary tactic to accelerate reclamation. This research aimed to evaluate the potential ameliorative effect of seven organic/inorganic amendments addition on soil properties and the differential responses of three rice genotypes under saline-sodic soil conditions at north of Egypt. A 2-year (2019 and 2020) field experiment was conducted with three rice genotypes, viz., Sakha 106, Giza 179, and Egyptian hybrid rice 1 (EHR1) cultivated in saline-sodic-affected soil amended with seven organic/inorganic amendments, i.e., gypsum, rice straw compost (RSC), farmyard manure (FYM), sulfur, sulfuric acid, calcium superphosphate, and rice husk beside control (unamended soil). This experimental design was a two-factor strip plot with randomized complete blocks with four replications. The morpho-physiological (SPADchlorophyll, water content, leaf area index, and shoot dry weight) and biochemical (catalase (CAT) activity, proline content, carbohydrates, leaf sodium (Na+) and potassium (K+), and Na+/K+ ratio) responses, the associated soil physico-chemical and microbial properties, yield, and its components were determined. RSC, gypsum, or sulfur were the most effective amendments in ameliorating saline-sodic soil properties by significantly reducing electrical conductivity, bulk density, and pH compared to the control and initial soil. Gypsum, RSC, FYM, or sulfur amendments significantly decreased the soil Na+ by 14.2, 11.7, 9.1, and 8.3%; sodium adsorption ratio by 14.9, 12.6, 10.4, and 8.7%; and exchangeable sodium percentage by 13.5, 11.5, 9.3, and 8.2%, respectively, over both seasons compared with control. The organic amendments surpassed inorganic regarding microbial biomass carbon, soil respiration rate, and dehydrogenase activity with the superiority of RSC, FYM, and rice husk over the control treatment. These soil restorations were favorably reflected in morpho-physio-biochemical parameters, yield, and its components for all the tested rice genotypes. The EHR1 is the superior genotype in terms of ion (Na+ and K+) selectivity, CAT activity, possessing lower proline and higher morpho-physiological responses, and productivity. The EHR1 had a considerable physiological effect on saline-sodic soil stress, producing higher yield (7.70 and 7.50 t ha−1) after treating with RSC or gypsum. This indicates that RSC outperforms other amendments in improving saline-sodic soils and enhancing rice productivity. Overall, a single application of rice straw compost (organic amendment) and gypsum or sulfur (inorganic amendment) is a viable sustainable approach for modulating saline-sodic soil’s physico-chemical and microbial properties and for boosting rice’s agronomic and physiological responses in an arid environment.

Long-term (nearly a century) effects of fertilizer, lime and rice straw compost application on active aluminum and iron and available phosphorus in paddy fields

In paddy soils, plant availability of phosphorus (P) increases during the flooding period due to the reductive dissolution of iron (Fe)-bearing minerals on which P is sorbed. Soil chemical properties are a determining factor of P availability and are subject to change after prolonged paddy rice cultivation. The purpose of this study was to evaluate the effects of long-term application of rice straw compost and slaked lime on changes in soil chemical properties, particularly focusing on the increase in available P under reductive conditions. The rice cultivation experiment was launched in 1926 to clarify the effects of mineral fertilizer (NPK), rice straw compost, and slaked lime application on soil properties. The amount of P solubilized under reductive conditions was evaluated by the difference in the P extracted by the Bray II method with and without reductive treatment of the soil. Continuous application of NPK mineral fertilizer without slaked lime resulted in higher amounts of aluminum extracted by acid ammonium oxalate and P extracted by the Bray II method until the 92nd cropping, while the increase in the proportion of available P under reductive conditions was low. In contrast, the amounts of Fe extracted by acid ammonium oxalate and P solubilized under reductive conditions were higher with increasing application of compost. The application of the compost caused strongly reductive conditions in the soil during the flooding period, and the dissolution of P in the Fe-bound fraction was facilitated. However, excessive application of compost led to the dissolution of high amounts of Fe-bound P, resulting in a loss of Fe and P from the cultivated soil. These results suggest that excessive application of rice straw compost and no application of slaked lime may cause a decrease in available P in paddy soils.

Application of composts and potassium sulphate on root rot incidence, morphological growth, yield components, oil content and constitutes of marjoram plants (Majorana hortensis L.)

Isolation of root rot tissue of diseased marjoram plants, yielded isolates fungal genera of Fusarium spp. and Rhizoctonia solani. Isolates of F. monoliforme and F. oxysporum, causing the highest root rot percentage and disease severity of marjoram plants in pot experiment. In the field, soil amendement with either composts of sugarcane bagasse, soybean straw and rice straw and in combination with potassium sulphate at (50 or 75 kg/feddan.). Results obtained indicated that, application of rice straw compost in combination with potassium sulphate (K2O) at 75 kg was the best treatment reduced root rot incidence of marjoram plants and highly significantly increased, plant height, fresh and dry weigh, yield components, content and percentage of essential oil as well in volatile oil high percentage of terpinene -4-ol (42.9%). Meanwhile, the high percentage of linalyl acetate (34.6%) in the application of (K2O) at 75 kg/feddan combined with soybean compost and carvacrol (32.3%) in the application of (K2O) at 75 kg/feddan. So, integration application of composts with (K2O) could be used as alternative strategies to fungicides for controlling root rot disease in marjoram, enhanching plant growth, yield components and constitutes of essential oil.

Trichoderma inoculants and straw compost improved resilience and yield in Cu-contaminated rice paddies

Abstract. Cuevas VC, Banaay CGB. 2022. Trichoderma inoculants and straw compost improved resilience and yield in Cu-contaminated rice paddies. Nusantara Bioscience 14: 1-9. Rice paddies in Marinduque, Philippines, are copper-contaminated from tailings of two mining companies formerly operating in the province. At present, paddy-soil copper concentration ranges from 22-386 mg kg-1. Crops suffer from copper toxicity and water stress due to climate-related events. The field study was conducted to investigate the ability of in situ composted rice straw and Trichoderma microbial inoculant (TMI) to mitigate rice productivity constraints. In treated set-ups, rice straw was scattered on the paddy after harvest. Triple 14 mineral fertilizer was mixed with Trichoderma compost activator, broadcasted over the straws, and subsequently incorporated into the soil during land preparation. Rice seeds were TMI-coated before sowing. Rice straw composting was not done in control set-ups, and seeds were uncoated. Mineral fertilizers were applied to both set-ups. Furthermore, set-ups were categorized based on soil Cu content, such as normal, moderate, and high. Four replicates were made per season and category. In treated paddies, rice leaves did not show yellowing, indicating adequate N mineralization and plant uptake. The difference in yield was significantly higher (81%) in treated paddies compared to control. During severe drought conditions, the mean yield in treated paddies was 1.8 t ha-1, while that of control paddies was zero. The yield was significantly correlated with K inputs mainly by compost in treated paddies. The application of rice straw compost and Trichoderma inoculants can be an adaptive strategy for climate change resilience and mitigation of copper toxicity in crops.

Effect of Application of Rice Husk Ash and Rice Straw Compost on Chemical Properties of an Ultisol Soil under Sweet Corn

This study aimed to determine the effect of rice straw compost and rice husk ash on some chemical properties of an Ultisol soil under sweet corn plant. This study was conducted at the Labuhan Batu Rantau Prapat University Campus Land and the PT. Socfindo Laboratory. The design used in this study was a randomized factorial design consisting of two factors with two replications. The first factor was the application of rice husk ash with four dose levels (g 5 kg -1 of soil), i.e. P0 (0), P1 (10), P2 (20), and P3 (30). The second factor was the application of rice straw compost with four dose levels (g 5 kg -1 of soil), i.e. J0 (0), J1 (25), and J2 (50), J3 (75). Results of this study indicated that the application of rice straw compost significantly increased soil organic-C and available P contents, as well as plant height, plant dry weight, N and P uptake by the plant. The treatments, however, did not significantly increase soil pH and total-N content. The application of rice husk ash significantly increased soil organic-C content and N uptake by the plant, but it did not significantly increase pH, available P content, and total N content of the soil.

Effect of Application of Rice Straw Compost and Tithonia (KOJETO) on Chemical Properties of Psament

Psament is a soil that has a low fertility rate which is characterized by low organic matter content (BO) so there are less water and nutrients available. Utilization of Psament for agricultural development must first be improved through other inputs such as BO and lime. This study aims to look at the interaction between KOJETO types and KOJETO doses on the chemical properties of Psament, to look at the effect of KOJETO types on the chemical properties of Psament, and to look at the effect of increasing KOJETO doses on the chemical properties of Psament. This research was conducted at the Wire House and Soil Laboratory of the Faculty of Agriculture, Andalas University, Padang. The experiment was designed according to a Factorial Randomized Complete Design with 2 factors and 3 replications. The main factor was the type of KOJETO which consisted of KOJETO A (0.75 PB Recommendations); KOJETO B (1 PB recommendation); KOJETO C (1.5 PB Recommendations). The second factor was KOJETO dose which consisted of (2.5, 5.0, 7.5, and 10.0) t ha -1 . The results showed that the type of KOJETO with several doses interacted to increase the chemical properties of Psament with the highest value in the KOJETO C treatment with a dose of 10.0 t ha -1 namely N-total content of 0.34 %, CEC 15.87 cmol kg -1 , Ca dd 1,27 cmol kg -1 and Mg dd 0.69 cmol kg -1 . The application of KOJETO C yielded the highest values of C-organic 2.80 %, K dd 0.53 cmol kg -1 and Na dd 0.51 cmol kg -1 . The single effect of increasing dose with the highest values at 10 t ha -1 were soil pH 5.80, P-available 14.59 ppm, C-organic 2.89 %, K dd 0.52 cmol kg -1 and Na dd 0.50 cmol kg -1 .

Effect of the long-term application of organic matter on soil carbon accumulation and GHG emissions from a rice paddy field in a cool-temperate region, Japan-II. Effect of different compost applications-

ABSTRACT The influence of long-term application of different types of compost on rice grain yield, CH4 and N2O emissions, and soil carbon storage (0 − 30 cm) in rice paddy fields was clarified. Two sets of paddy fields applied with rice straw compost or livestock manure compost mainly derived from cattle were used in this study. Each set comprised long-term application (LT) and corresponding control (CT) plots. The application rates for rice straw compost (42 years) and livestock manure compost (41 years in total with different application rates) were 20 Mg fresh weight ha–1. Soil carbon storage increased by 33% and 37% with long-term application of rice straw compost and livestock manure compost, respectively. The soil carbon sequestration rate by the organic matter application was 23% higher with the livestock manure compost than with the rice straw compost. The rice grain yield in the LT plot was significantly higher than that in the corresponding CT plot with both types of compost. Although the difference was not significant in the rice straw compost, cumulative CH4 emissions increased with long-term application of both composts. Increase rate of CH4 emission with long-term application was higher in the livestock manure compost (99%) than that in the rice straw compost (26%). In both composts, the long-term application did not increase N2O emission significantly. As with the rice straw compost, the increase in CH4 emission with the long-term application of livestock manure compost exceeded the soil carbon sequestration rate, and the change in the net greenhouse gas (GHG) balance calculated by the difference between them was positive, indicating a net increase in the GHG emissions. The increase in CH4 and net GHG emissions owing to the long-term application of the livestock manure compost could be higher than that of the rice straw compost owing to the amount of applied carbon, the quality of compost and the soil carbon accumulation. The possibility that carbon sequestration in the subsoil differs depending on the type of composts suggests the importance of including subsoil in the evaluation of soil carbon sequestration by long-term application of organic matter.

Application of Rice Straw Compost with Different Bioactivators on the Growth and Yield of Rice Plant

Turnover of organic matters to the soil can increase the efficiency of chemical fertilizers, improve the plant growth and sustain the environment. Field experiment was carried out in the Buyut Udik Village, Gunung Sugih District, Central Lampung from May to August 2009. Rice straw was composted by three kinds of decomposer (bioactivator A, B, and C). Rice straw compost (2 Mg ha-1) was applied to the paddy-field soil that was planted by rice (Oryza sativa) of Ciherang Variety. The experiment was arranged in a randomized block design with three replicates. The results showed that application of rice straw compost reduced the numbers of empty grain per tiller compared to control (without compost) in which control had the highest percentage of empty grain (15.9%). The application of rice straw compost that was decomposed by bioactivator A gave the highest numbers of grain per panicle and yield per plot as followed 162.5 seed and 33 kg plot-1, respectively. Application of various rice straw composts that were decomposed by three kinds of bioactivator increased the rice grain up to 13-26% compared to control.

The effects of potassium, nitrogen and straw compost giving to increase organic material levels and k-exchangeable rice fields and rice growth

Potasium and nitrogen fertilization accompanied by the application of rice straw compost is expected to improve the chemical properties of rice fields and the growth of rice plants. The purpose of this research is to find out the effect of potassium, nitrogen and straw compost fertilizer on increasing C-organic, organic matter and K-exchangeable soil and the growth of rice plants. This research was conducted in the rice field area of Cengkeh Turi village, Binjai City (± 32 m asl) from March-July 2018. This study used factorial randomized block design method with 3 Factors: Potassium (KCL): 0. 25. 50 and 75 kg ha−1; Nitrogen (Urea): dosage for farmers (250 kg ha−1) and LCC recommendations (315 kg ha−1); straw compost Treatment: without compost straw (0 t ha−1) and straw compost (5 t ha−1). The results showed that the application of potassium, nitrogen and straw compost had no significant effect on increasing levels of C-organic, organic matter and K-exchangeable paddy soil. However. There was an increase in nutrient status from very low to low. While there is a significant effect on plant height and number of tillers per clump at 2 weeks after planting and shoot dry weight of rice plants.

Effects of incubation period and Christmas Island rock phosphate with different rate of rice straw compost on phosphorus availability in acid soil

Phosphorus (P) availability is limited in tropical acid soil due to fixation of soluble inorganic P by aluminium (Al) and iron (Fe). Liming is one of the common ways to overcome this problem. However, this practice is not economical. The aim of this study was to evaluate the effects of laboratory incubation period and different rates of rice straw compost on the soil P availability. During the incubation study, Christmas Island rock phosphate (CIRP) fertilizer was amended with different rates of rice straw compost (5, 10, 15, and 20 t ha−1). Treatments were incubated in the laboratory for 30, 60, and 90 days. Application of rice straw compost with CIRP significantly increased soil available P at 30, 60, and 90 days of incubation, respectively. This implies rice straw compost plays an important role on soil P availability by decreasing the P adsorption due to the competing adsorption sites by organic anion and dissolving the mineral associated P by low-molecular-weight organic acids. Besides, rice straw compost also increased the soil pH, and, at the same time, reduced exchangeable acidity, exchangeable Al and Fe. As the soil pH increased, the compost effectively fixed the Al and Fe in the soil instead of P, thus increasing the P availability in the soil. However, there was no significant increase/loss of available P when the incubation time increases under treatments with rice straw compost. This implies the effectiveness of rice straw compost in minimizing the loss of P due to P fixation in soil and slow microbially mediated mineralization of soil organic P to inorganic P as incubation time increases. The findings suggest that the application of rice straw compost altered soil chemical properties in a way that enhanced the availability of P in the Rengam acidic soil.

Effects of soil type and organic fertilizers on fatty acids and vitamin E in Korean ginseng (Panax ginseng Meyer)

This study examined the effects of soil type and fertilizer regimes on variations in fatty acids (FAs) and vitamin E (Vit-E) in 6-year-old ginseng roots. We observed significant variation in both FA and Vit-E contents owing to the type and quantity of organic fertilizer used in each soil type during cultivation. Unsaturated FAs were approximately 2.7-fold higher in ginseng than in saturated FAs. Linoleic, palmitic, and oleic acids were the most abundant FAs detected in ginseng roots. Additionally, α-tocopherol was the major Vit-E detected. In particular, the increased application of rice straw compost or food waste fertilizer elevated the quantity of nutritionally desirable FAs and bioactive Vit-E in ginseng root. Partial least square-discriminant analysis (PLS-DA) score plots showed that soil type might be the main cause of differences in FA and Vit-E levels in ginseng. Specifically, the PLS-DA model indicated that palmitic acid is a suitable FA marker in determining whether ginseng plants were grown in a paddy-converted field or an upland field. Moreover, linoleic acid levels were highly correlated with α-linolenic acid (r=0.8374; p<0.0001) according to Pearson's correlations and hierarchical clustering analysis. Hence, these preliminary results should prove useful for the reliable production of ginseng containing high phytonutrient quantities according to cultivation conditions.

Effects of the Continuous Application of Rice Straw Compost and Chemical Fertilizer on Soil Carbon and Available Silicon under a Double Rice Cropping System in the Mekong Delta, Vietnam

Effects of the Continuous Application of Rice Straw Compost and Chemical Fertilizer on Soil Carbon and Available Silicon under a Double Rice Cropping System in the Mekong Delta, Vietnam

Effects of Rice Straw Compost Application on Exchangeable Potassium in Long-term Fertilization Experiments of Paddy Soils

In an experiment conducted at the research field of the National Institute of Agricultural Science, we investigated the effects of mineral fertilizer and rice straw compost on exchangeable potassium and K balances, and rice grain yield under a rice single system. The treatments were no fertilization (No fert.), inorganic fertilization (N), inorganic fertilizer (N, P, K) plus rice straw compost at rates of 7.5, 15.0, 22.5, and 30.0 ton ㏊ -1 (NPKC7.5, NPKC15.0, NPKC22.5, and NPKC30.0, respectively). The inorganic fertilizers (N, P, K) were added with standard fertilizer application rate in which nitrogen (N), phosphate (P₂O₅), and potassium (K₂O) were applied with 75∼150 ㎏ ㏊ -1 , 70∼86 ㎏ ㏊ -1 , 75∼86 ㎏ ㏊ -1 , respectively. Exchangeable potassium for NPKC15.0 NPKC22.5, and NPK30.0 treatments was higher by 0.05~0.19 cmolc ㎏ -1 than thatof NPKC7.5 treatment. Increasing levels of rice straw compost resulted in an increase in the K balance from –19.9 ㎏ ㏊-1 yr -1 (No fert.) to 41.9 ㎏ ㏊ -1 yr -1 at NPKC22.5 treatment and 62.9 ㎏ ㏊ -1 at NPKC30.0 treatment.Continuous application of rice straw compost with NPK fertilizers affected significantly the rice grain yields. The result of the study imply that the application of more than 22.5 ton ㏊ -1 of rice straw compost with NPK fertilizers are recommended as the best fertilization practice for enhancement of crop production and K supplying power of soil in the continuous rice cropping system.

Effect of Decomposition on Nitrogen Dynamics in Soil Applied with Compost and Rye

Soil organic matter (SOM) plays an important role in the continuous production and environmental conservation in arable soils. In particular, the decomposition of organic matter in soil might promote soil organic matter and fertility due to the mineralization of N. In this study, to evaluate the effect of organic matter amendment on the C mineralization and N dynamic, CO₂-C flux, extractable N and N₂O emission were determined using closed chamber for 4 weeks at 10, 15, 20°C of incubation temperature after the mixture of 2 Mg ha -1 rice straw compost and rye in sandy loam and clay loam. Regardless of soil texture, decomposition rates of rice straw compost and rye at 10~20°C of incubation temperature ranged from 0.9 to 3.8% and 8.8 to 20.3%, respectively. Rye application in soil increased NH₄-N and NO₃-N content as well as the N₂O emission compared to the rice straw compost. After incubation for 4 weeks, total C content in two soils was higher in rice straw compost than in rye application. In conclusion, application of rice straw compost and rye to soil was able to improve the soil organic matter and fertility. However, organic matter including the recalcitrant compounds like rice straw compost would be effective on the management of soil organic matter and the reduction of greenhouse gases in soil.

EFFECT OF COMPOST AND COMPOST TEA APPLICATION ON FABA BEAN CROP AND SOME SOIL BIOLOGICAL AND CHEMICAL PROPERTIES

The objective of this investigation was to study the effect of addition of organic matter i.e, composted rice straw, compost tea and their interaction on the yield and seed nutrients content of faba bean (vicia faba L.) cv. Sakha 1 and some soil biological and chemical properties. A field experiment was conducted in the Experimental Farm of Sakha Agric. Res. Station in two successive winter seasons of 2010/2011 and 2011/2012. Results showed that soil organic matter content was increased, while values of soil salinity (ECe) were reduced and there was a slight reduction in soil pH with compost addition at rates 2 and/or 4 tons/fed. Data recorded the highest significant increases in nodule numbers and its dry weight as compared to control. Also, these treatments recorded significant increases the biological activity of soil in terms of increasing the soil total bacteria, as well as dehydrogenase activity and nitrogenase activity that increase the soil fertility, improved plant quality, as well as environmentally safe and eco-friendly, that positively turn on faba bean yield production. The interaction between compost and compost tea gave better results in increasing the seed yield especially for application of 4 tons /fed with compost tea spraying at 50 days after sowing increased the seed yield by 51%, 53.1% relative to control in the two seasons (2010/2011 and 2011/2012), respectively. Nutrients content (N, P and K) of faba bean seeds was significantly increased in all treatments compared with the control. Also, the results showed that application of rice straw compost was effective for increasing available N, P and K in soil as compared to the control. Based on the results of the current study, the combinations between rice straw compost and compost tea are considered as an integrating nutrient management to improve the soil biological and chemical properties and yield of faba bean crop.

Combined Effects of the Continual Application of Composted Rice Straw and Chemical Fertilizer on Rice Yield under a Double Rice Cropping System in the Mekong Delta, Vietnam

We conducted a 12-year field experiment to study the combined effects of rice straw compost and chemical fertilizer application on a double rice cropping system in the Mekong Delta, Vietnam and established 7 treatments using a randomized block design with 3 replications. We calculated the yields of treatments relative to those of conventionally fertilized plots (i.e. with no added rice straw compost), and analyzed their annual trends. In the plots with rice straw compost, we observed a positive trend over 12 continuous wet cropping seasons. In comparison with conventional fertilization, the application of rice straw compost with reduced chemical fertilizer can maintain rice productivity over a longer period. We analyzed the nutrient status of the rice straw at harvest over 4 cropping seasons and observed that the Si concentration of the rice straw in conventionally fertilized plots was significantly lower than that in the plots where rice straw compost was applied. The N, P and Mg concentrations of the rice straw increased with the fertilizer application rate, while the concentrations of K, Ca, Mn, Fe, Zn, and Cu did not differ significantly among treatments. Our results suggest that continuous removal of rice straw may reduce the Si availability in soil, thereby decreasing rice productivity. In addition, we verified that rice straw compost can be an effective source of silicon for paddy rice. Discipline: Soils, fertilizers and plant nutrition Additional key words: nutrient balance, silicon, soil fertility, sustainable land use

논 토양의 유기탄소 변동에 관한 비료와 개량제의 장기연용 효과

The changes of soil organic carbon (SOC) content in paddy soils (sandy loam) were assessed from data of the 59 years fertilization plots in which the continuous rice cropping experiment started in 1954. The treatments were no fertilization(no fert.), NPK fertilization (N, NPK), NPK plus rice straw compost (NPK+C), and NPK plus rice straw compost, silicate fertilizer and lime (NPK+CLS). After 41 years, SOC content in NPK+C and NPK+CLS treatment in surface soils (0~15 cm) reached at the highest, followed by maintaining a plateau level for 8 years. After 51 years, they showed a tendency to decrease. Peak concentrations of soil organic carbon were in NPK+CLS, in NPK+C, in NPK, in N, and in control. Dissolved organic carbon(DOC) contents in surface soil solution were about 2.3 times higher in NPK+C than that in NPK+CLS. Therefore, SOC in subsurface soil(15~30 cm) was greater in NPK+C than the other treatments. These results indicate that continuous application of rice straw compost and silicate fertilizer affected significantly on the level of SOC in surface soils, subsurface soils, and soil solutions. Thus, the combined applications of NPK fertilizers with organic compost and silicate as a soil amendment are recommended as the best fertilization practice for soil carbon accumulation, environment conservation, and enhancement of soil fertility status in the continuous rice cropping system.

Application of Rice Straw Compost with Different Bioactivators on the Growth and Yield of Rice Plant

Turnover of organic matters to the soil can increase the efficiency of chemical fertilizers, improve the plant growth and sustain the environment. Field experiment was carried out in the Buyut Udik Village, Gunung Sugih District, Central Lampung from May to August 2009. Rice straw was composted by three kinds of decomposer (bioactivator A, B, and C). Rice straw compost (2 Mg ha-1) was applied to the paddy-field soil that was planted by rice (Oryza sativa) of Ciherang Variety. The experiment was arranged in a randomized block design with three replicates. The results showed that application of rice straw compost reduced the numbers of empty grain per tiller compared to control (without compost) in which control had the highest percentage of empty grain (15.9%). The application of rice straw compost that was decomposed by bioactivator A gave the highest numbers of grain per panicle and yield per plot as followed 162.5 seed and 33 kg plot-1, respectively. Application of various rice straw composts that were decomposed by three kinds of bioactivator increased the rice grain up to 13-26% compared to control.

Heavy Metal Reductions in Soils Amended With Compost and Water Treatment Residuals

The present work was carried out to evaluate the effect of rice straw compost, water treatment residuals (WTR), and their mixture (2:1 and 1:1 wet weight), on heavy metal immobilization in contaminated soils and on growth of canola (Brassica napus). The results showed that the Pb, Cd and Zn concentrations were significantly reduced in the root and shoot of canola plant grown with the application of rice straw compost and WTR amendment. Extractability of the metals was also significantly reduced in this treatment compared with the control. The dry weight and root depth of canola plants were significantly increased with the application WTR and compost treatments at two levels 10 or 20 mg kg−1 soil compared with the control. The addition of compost and WTR (2:1 or 1:1 wet weight ratio) at 10 g dry weight kg−1 dry soil gave the best reduction in the soil metal extractability and in plant growth compared with other treatments. Thus, the combination of rice straw compost and WTR was successful in lowering the bioavailability of metals and increasing yield of canola grown on the contaminated soil.