The objective of this study was to investigate varietal differences in dry matter production and physiological nitrogen use efficiency (PNUE) using a wide range rice (Oryza sative L.) varieties at an early growth stage. results provide useful information for breeding suitable cultivation under conditions low soil fertility or with reduced fertilizer sustainable agriculture. Thirty-one were used, seedlings grown 8 treatment conditions. effects natural variations embryo and/or endosperm size...

This study aimed at understanding whether and how long-term organic rice farming affects soil carbon (C) nitrogen (N) stocks their mineralization potentials in submerged paddies Tochigi, Japan. An incubation experiment was carried out to assess the impacts of internal nutrient cycling after (OF) for 4–5 years (4OF), 8–9 (8OF), 12 (12OF), compared with a conventional field (CF). Soil samples were collected 0–15 cm 15–20 flooded fields harvest October 2013. pH bulk density significantly lower...

Abstract We examined the effect of seed nitrogen content on rates germination, emergence, and establishment rice plants. Several lots with various contents were obtained from parent plants grown under 3 planting densities 4 application. There was a clear negative correlation between germination time (R =0.88), whereas dry weight very low (R=0.23). The lot high absorbed water faster than content, especially first day after soaking, also showed exsertion fourth leave, more uniform germination....

Abstract The electrochemical behavior of Clostridium pasteurianum ferredoxin and spinach was studied by cyclic d.c. phase-selective a.c. voltammetry with a hanging mercury drop electrode. An irreversible adsorption these ferredoxins on the electrode surface is described. In successive voltage scans both voltammograms change gradually in height form until steady state attained, indicating that adsorbed decompose to cluster-free ferredoxins. Apoferredoxins give same as are assigned RSH/RSHg...

The System of Rice Intensification (SRI) is based on a set practices such as transplanting young seedlings and aerobic soil management during the vegetative stage without using costly external input, which attracted rice researchers because higher yields compared with conventional flooded practices. This review assesses some field data for SRI performance in light current knowledge about certain agronomic practices, focusing particularly nitrate production paddy possible effect differences...

Abstract The electrochemical behavior of Clostridium pasteurianum ferredoxin (Cl.Fd) was studied by a.c. polarography with the dropping mercury electrode. polarograms observed in acidic media (pH<7) were assigned to RSH/RSHg redox reaction cysteine residues apoferredoxin, whereas those basic (pH>8) a two-step one-electron transfer (EE mechanism) iron-sulfur clusters Cl.Fd adsorbed on electrode surface ((Cl.Fd)ad). polarographic (Cl.Fd)ad interpreted theory reaction. formal...

Precision agriculture has been developed in order to achieve more productive, profitable and environmentally sound by adjusting the input level site-specific manner. Therefore, delineation of management zone spatially variable farmland was thought be crucial for a crops. Recent introduction ICT (Information Communication Technology) precision however, changed concept zone. Advancement enable produce prescriptions tailored each field integrating soil fertility map, quasi real-time crop growth...

Foxtail (Alopecurus aequalis) and milk vetch (Astragalus sinicus) are typical winter weeds grown in single-cropping rice fields during the fallow season central Japan. These generally incorporated into soil as green manure plowing, before transplanting, to improve fertility yield. To understand carbon (C) decomposition nitrogen (N) mineralization behavior of organic farming, we carried out two experiments. Firstly, examined effect adding 1% foxtail soils that were sampled from farmed...

We studied soil nitrogen (N) management in a farmer's organic rice farming Japan, where the farmer applied no external N but incorporated gramineous fallow weeds and residues as situ sources. focused on effect of weed incorporation N-supplying capacity paddy by tracking decomposition 15N-labeled after incorporation. The result fits well to first order kinetics with rate 34.3% year. A model accumulation mineralization based showed that originated from would become saturated at level 1.92...

The current study initiated to investigate crop coefficient (Kc) and water productivity between conventional System of Rice Intensification (SRI) irrigation regimes terrace rice fields in Indonesia. Kc value represents plant responses available the its information is very important determine evapotranspiration. field experiments were conducted belong local farmer located Wonogiri, Central Java (S 7o47’18.66”, E 111o5’51.26”) during 21 July – 7 November 2014 dry season. Here, there two with...

Abstract We examined the relationship between form of iron and tillability (defined as degree ease pulverizing a soil into small clods) soils in upland fields that had been converted from paddy fields. The amount (Fe.e) extractable with acetate buffer (pH 3.0) decreased 0.959 g kg-1 field has continuously used to 0.104 kg-I an for period 5 y. There was no significant change free oxide content under conditions. These results indicate ferric oxides are gradually crystallized less reactive...

We investigated the amount of soil phosphorus (P) in a farmer's paddy fields under organic farming (OF) for various periods from 0 to 22 years as well other farmers' conventional farming. All are located allophanic Andosol with long history P fertilizer application, and some them have been converted OF across years. After conversion OF, was supplied only winter fallow weeds mainly Foxtail (Alopecurus aequalis), rice residues (rice bran straw), guano. determined total-P (Tot-P)...