Direct and Residual Effects of Fly Ash-Based Integrated Fertilization on Rice (Oryza sativa L.) and Rapeseed (Brassica camprestris L.)

Integrated effects of fly ash (FA), farmyard manure (FYM), and chemical fertilizers recommended dose of fertilizer (RDF) on the performance of rice (Oryza sativa L.) and their residual effect on rapeseed (Brassica camprestris L. vartoria) were studied for two years in loamy acidic inceptisol of Assam, India.

The FA was generated from a bituminous and lignite coal-based captive thermal power plant of Hindustan Paper Corporation Ltd (HPCL), Assam. Rice yields were higher when FA, FYM, and RDF were used collectively vis-à-vis sole application of RDF reflected also in rapeseed under residual effect . FA effect on mean rice equivalent yield of the rice–rapeseed system was the highest (24.4%) under integrated application. Nickel (Ni) and cadmium (Cd) contents in rice decreased with increasing FA, while arsenic (As) was just the opposite. Integration of FA, FYM, and RDF was effective in lowering Ni, Cd, and As in rice compared to 100% RDF alone or together with FA. The residual effect on rapeseed was similar for Ni and As while the Cd content increased. Blending of FA, FYM, and RDF also positively altered the residual soil pH, organic carbon (C), and nitrogen, phosphorus, and potassium (NPK). Thus, FA can be an integral component of integrated plant nutrition system (IPNS) in augmenting crop yield and residual benefits in loamy acid inceptisol.     

Temporal variation of soil nutrients under the influence of different organic amendments

Maintenance of tropical soil quality for crop production without damaging the environment is a challenge and thus the development of an efficient nutrient-management technique is important. Soil amendment by organic manures has been widely accepted as an efficient nutrient-management technique in tropical agriculture. In this study, a long-term laboratory experiment was conducted to investigate the influence of organic manures of different sources (e.g. cattle manure, poultry manure, vermicompost and oil cakes) on changes in pH, electrical conductivity, organic C and nutrient content (mineral N, available phosphorous and potassium) in tropical alluvial soil. Applications of organic amendments in this study indicated considerable changes in the basic soil physico-chemical properties and different nutrient levels. Soil pH declined slightly, whereas organic C and all the other nutrients increased distinctly, due to the application of organic manures. Thus, the magnitude of changes in the soil properties was dependent on the nature of the organic manure.     

Simulation Model for Composting Cellulosic (Bagasse) Substrates

A dynamic model of aerobic composting with solid substrates was developed as a first step to predict the rate of decomposition of cellulosic materials. The model was based on heat and mass transfer principles and reaction kinetics of biological processes. The relations describing the rates of reaction and the degradability potential of the substrates were determined based on laboratory-scale experiments. The model was developed using a graphical software package, Stella II® (which was able to solve feedback loops encountered in actual composting processes.

The model was validated with temperature, oxygen distribution and mass degradation accompanying the composting of bagasse. Experimental setups consisted of 30 gallon drum reactors, continuously aerated. Temperature and oxygen in exhaust gases were monitored on an hourly basis and measurements of moisture content, pH and volatile solids were done on a weekly basis.

The data fit with the model was excellent for mass degraded and temperatures for the first 10 days. From day 10 to 14, the deviations between model predictions (as solved with Stella II®) and actual measurements did not exceed 2.6 percent. The concentrations of oxygen in outlet gases showed fair agreement between predicted and experimental values. Simulating the model with varying airflow rates showed that the maximum mass breakdown rates occurred for airflow rates of 0.12 kg dry air/(kg dry compost.hr) while maintaining the temperatures below 50°C, through a temperature feedback control strategy.     

Effect of biofertilizers on the nutrient availability in soil in relation to growth,yield and yield attributes of Stevia rebaudiana

A field experiment was conducted at Rani Chandramma Agricultural University (Arabhavi, Belgaum), Karnataka, India, in basic soil to study the nutrient availability in soil, yield and yield attributes of the medicinal plant stevia (Stevia rebaudiana). The results showed that the availability of nutrients such as nitrogen (N), phosphorus (P) and potassium (K) in the soil increased up to the fifth month; and thereafter, decreased by the same amount with the progress of the plant growth up to the sixth month, irrespective of treatments. Results also showed that the fresh and dry biomass yields significantly increased up to the sixth month with different treatments, but the yield attributes like plant height and the number of branches were observed to be varied with various treatments, being highest in the combined application of biofertilizers over that of their corresponding sole applications.     

Comparison of cardioprotective abilities between the flesh and skin of grapes

Recent studies have documented that grapes and grape juices are equally cardioprotective as red wine. The existing reports implicate that the skin and seeds of the grapes containing polyphenolic antioxidants are instrumental for the cardioprotective properties of grapes. The present study examines if the flesh of grapes also possesses any cardioprotective abilities. Three groups of randomly selected rats were fed, water only (control), flesh of the grapes (2.5 mg/kg b. wt.) or the skins (2.5 mg/kg b. wt.) for 30 days. At the end of the 30 days, isolated perfused hearts were made ischemic for 30 min followed by 2 h of reperfusion in the working mode. The results demonstrated that both flesh and skin of the grapes could protect the hearts from ischemic reperfusion injury as evidenced by improved postischemic ventricular recovery and reduced myocardial infarct size. High performance liquid chromatography (HPLC) revealed that skin and flesh contained comparative amounts of glucose, fructose, tartaric acid, malic acid, shikimic acid, and trans-caftaric acid. In addition, the flesh contained reduced amounts (compared to skin) of cis-coutaric, trans-coutaric, caffeic, p-coumaric, cinnamics, and catechin/epicatechin. Total polyphenolic index was also lower in flesh compared to skin. The anthocyanins were present exclusively in the skin. Electron paramagnetic resonance (EPR) spectrometry of hydroxy radicals indicated that both flesh and skins possessed equal amount of ROS scavenging activities. Total malonaldehyde content in the heart was reduced comparatively with either flesh or skin. The results indicate for the first time that the flesh of grapes are equally cardioprotective as skin, and antioxidant potential of skin and flesh of grapes are comparable with each other despite of the fact that flesh does not possess any anthocyanin activities.     

Can conservation tillage and residue management enhance energy use efficiency and sustainability of rice-pea system in the Eastern Himalayas?

ABSTRACT

Low productivity and energy use efficiency (EUE) of rice farming are the major concerns for agricultural sustainability in the Eastern Himalayan region of India. A field experiment on rice (Oryza sativa L.)-pea (Pisum sativum L) system was conducted for three consecutive years during 2012–15 in lowland ecosystem to assess the direct and residual impact of tillage and residue management (RM) practises on productivity and sustainability. Significantly higher grain yield of rice was achieved under no-till (NT) than minimum tillage (MT) and conventional tillage (CT). Among RM practises, 50% NPK + green leaf manure, 50% NPK + weed biomass and 50% NPK + in-situ residue retention recorded significantly higher mean grain yields than application of 50% NPK and 100% NPK without residues. Residual effect of MT in preceding rice gave significantly higher green pod yield of succeeding pea than NT and CT. The system EUE was significantly higher under MT (rice)-NT (pea) compared to those of NT-NT and CT-NT systems. The sustainable yield index of rice and pea was maximum under MT-NT followed by NT-NT. Thus, NT/MT with suitable RM practises is a pertinent strategy for sustainable productivity of rice-pea system in the Eastern Himalayas and in similar adjoining regions.     

Metabolism of metamitron in goat following a single oral administration of a nontoxic dose level: a continued study

Disposition kinetic behavior and metabolism studies of metamitron and its metabolite in terms of the parent compound were carried out in black Bengal goats after a single oral administration of a nontoxic oral dose at 30 mg kg(-1) of body weight. Metamitron was detected in the blood sample at 5 min (2.23 +/- 0.04 microg mL(-1)), maximum at 1 h (3.43 +/- 0.02 microg mL(-1)) and minimum at 12 h (0.41 +/- 0.01 microg mL(-1)), after a single oral administration. Metabolite [3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one] in terms of the parent compound was detected in the blood sample at 5 min (0.47 +/- 0.006 microg mL(-1)), maximum at 6 h (5.12 +/- 0.02 microg mL(-1)) and minimum at 96 h (1.06 +/- 0.016 microg mL(-1)), after a single oral administration. The t(1/2 K) and Cl(B) values of metamitron were 3.63 +/- 0.05 h and 1.36 +/- 0.016 L kg(-1) h(-1), respectively, whereas the t(1/2K)(m) and Cl(B)(m) values of the metabolite were 38.15 +/- 0.37 h and 0.091 +/- 0.001 L kg(-1) h(-1), respectively, which suggested long persistence of the metabolite in blood and tissues of goat. Metamitron was excreted through feces and urine for up to 48 and 72 h, whereas the metabolite was excreted for up to 168 and 144 h, respectively. Metabolite alone contributed to 96 and 67% of combined recovery percentage of metamitron and metabolite against the administered dose in feces and urine of goat, respectively. All of the goat tissues except lung, adrenal gland, ovary, testis, and mammary gland retained the metabolite residue for up to 6 days after administration.     

Effect of conservation agriculture on soil organic and inorganic carbon sequestration and lability: A study from a rice–wheat cropping system on a calcareous soil of the eastern Indo-Gangetic Plains

Increasing soil carbon (C) in arable soils is an important strategy to achieve sustainable yields and mitigate climate change. We investigated changes in soil organic and inorganic carbon (SOC and SIC) under conservation agriculture (CA) in a calcareous soil of the eastern Indo-Gangetic Plains of India. The treatments were as follows: conventional-till rice and wheat (CT-CT), CT rice and zero-till wheat (CT-ZT), ZT direct seeded rice (DSR) and CT wheat (ZT-CT), ZTDSR and ZT wheat without crop residue retention (ZT-ZT), ZT-ZT with residue (ZT-ZT+R), and DSR and wheat both on permanent beds with residue (PB-PB+R). The ZT-ZT+R had the highest total SOC in both 0–15 and 15–30 cm soil layers (20% and 40% higher (p < .05) than CT-CT, respectively), whereas total SIC decreased by 11% and 15% in the respective layers under ZT-ZT+R compared with CT-CT. Non-labile SOC was the largest pool, followed by very labile, labile and less labile SOC. The benefits of ZT and residue retention were greatest for very labile SOC, which showed a significant (p < .05) increase (~50%) under ZT-ZT+R compared with CT-CT. The ZT-ZT+R sequestered ~2 Mg ha⁻¹ total SOC in the 0–15 cm soil layer in 6 years, where CT registered significant losses. Thus, the adoption of CA should be recommended in calcareous soils, for C sequestration, and also as a reclamation technique.