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1.
Shekhar Shashank Mailapalli Damodhara Rao Raghuwanshi Narendra Singh Das Bhabani Sankar 《Paddy and Water Environment》2020,18(1):73-85
Paddy and Water Environment - Alternate wetting and drying (AWD) irrigation practice in paddy cultivation requires a safe soil moisture stress level in the root zone for which irrigation water... 相似文献
2.
Potato water use and yield under furrow irrigation 总被引：3，自引：0，他引：3
Field experiments were conducted to study the effects of plant-furrow treatments and levels of irrigation on potato (Solanum tuberosum L.) water use, yield, and water-use efficiency. The experiments were carried out under deficit irrigation conditions in a sandy loam soil of eastern India in the winter seasons of 1991/92, 1992/93, and 1993/94. Two plant-furrow treatments and two levels of irrigation were considered. The two plant-furrow treatments were F1 - furrows with single row of planting in each ridge with 45 cm distance between adjacent ridges, and F2 - furrows with double rows of planting spaced 30 cm apart in each ridge with 60 cm distance between adjacent ridges. The two levels of irrigation (LOI) were I1 - 0.9 IW/CPE and I2 - 1.2 IW/CPE, where IW is irrigation water of 5 cm and CPE is cumulative pan evaporation. Treatment F2 produced highest tuber yield in all years with average value of 10,610 kg ha -1 and 12,780 kg ha -1 at LOI of I1 and I2, respectively. On average, six irrigations with a total of 25 cm, and seven irrigations with a total of 30 cm were required for both treatments F1 and F2 at LOI of I1 and I2, respectively. Treatment F2 resulted in a significantly higher number of branches and tubers per plant, foliage coverage and water-use efficiency for both irrigation levels than treatment F1. Average daily crop evapotranspiration was found to range from 1.1 to 3.4 mm and from 1.2 to 3.9 mm for treatment F1 and from 1.1 to 3.6 mm and from 1.2 to 4.0 mm for treatment F2 at LOI of I1 and I2, respectively. 相似文献
3.
Treatment of wheat straw using tannase and white-rot fungus to improve feed utilization by ruminants
Background
Current research to enrich cattle feed has primarily focused on treatment using white rot fungi, while there are scarce reports using the enzyme tannase, which is discussed only in reviews or in the form of a hypothesis. In this context, the aim of the present study was to evaluate the effect of tannase on wheat straw (WS) and also the effect of lyophilized tannase at concentrations of 0.1%, 0.2%, and 0.3% (w/w) on WS followed by fermentation with Ganoderma sp. for 10 d and compared in relation to biochemical parameters, crude protein (CP) content, and nutritional value by calculating the C/N ratio in order to improve the nutritional value of cattle feed.Results
Penicillium charlesii, a tannase-producing microorganism, produced 61.4 IU/mL of tannase in 54 h when 2% (w/v) tannic acid (TA) was initially used as a substrate in medium containing (% w/v) sucrose (1.0), NaNO3 (1.0), and MgSO4 (0.08 pH, 5.0) in a 300-L fermentor (working volume 220 L), and concomitantly fed with 1.0% (w/v) TA after 24 h. The yield of partially purified and lyophilized tannase was 5.8 IU/mg. The tannin-free myco-straw at 0.1% (w/w) tannase showed 37.8% (w/w) lignin degradation with only a 20.4% (w/w) decrease in cellulose content and the in vitro feed digestibility was 32.2%. An increase in CP content (up to 1.28-fold) along with a lower C/N ratio of 25.0%, as compared to myco-straw, was obtained.Conclusions
The use of tannin-free myco-straw has potential to improve the nutritional content of cattle feed. This biological treatment process was safe, eco-friendly, easy to perform, and was less expensive as compared to other treatment methods. 相似文献4.
Comparative study of conventional and artificial neural network-based ETo estimation models 总被引：4，自引：3，他引：1
Accurate estimation of reference crop evapotranspiration (ETo) is required for several hydrological studies and thus, in the
past, a number of ETo estimation methods have been developed with different degree of complexity and data requirement. The
present study was carried out to develop artificial neural network (ANN) based reference crop evapotranspiration models corresponding
to the ASCE’s best ranking conventional ETo estimation methods (Jensen et al. ASCE Manual and Rep. on Engrg. Pract. no. 70,
1990). Among the radiation methods, FAO-24 radiation (or Rad) method for arid and Turc method for humid region, and among
the temperature methods, FAO-24 Blaney–Criddle (or BC) method were studied. The ANN architectures corresponding to the above
three less data-intensive methods were developed for four CIMIS (California Irrigation Management Information System) stations,
namely, Davis, Castroville, Mulberry, and West Side Field station. The comprehensive ANN architecture developed by Kumar et
al. (J Irrig Drain Eng 128(4):224–233, 2002) corresponding to Penman–Monteith (PM) ETo for Davis was also tried for the other
three stations. Daily meteorological data for a period of more than 10 years (01 January 1990 to 30 June 2000) were collected
from these stations and were used to train, test, and validate the ANN models. Two learning schemes, namely, standard back-propagation
with learning rate of 0.2 and standard back-propagation with momentum having learning rate of 0.2 and momentum term of 0.95
were considered. ETo estimation performance of the ANN models was compared with the FAO-56 PM method. It was found that the
ANN models gave better closeness to FAO-56 PM ETo than the best ranking method in each category (radiation and temperature).
Thus these models can be used for ETo estimation in agreement with climatic data availability, when not all required climatic
variables are observed. 相似文献
5.
To ascertain the reasons for poor nodulation of pigeonpea, we studied the effect of high temperature on the production of flavonoids by the pigeonpea host. A high temperature affected flavonoid production by pigeonpea and mungbean. At 37°C pigeonpea root exudates contained four flavonoids and the root extract contained five. The proportion of the second flavonoid in the pigeonpea and the mungbean was higher and the proportion of the third flavonoid was lower at 37°C compared to 30°C. At the higher temperature the flavonoids exuded from pigeonpea roots were same those in the root homogenate. 相似文献
6.
A. Bhadra A. Bandyopadhyay R. Singh N. S. Raghuwanshi 《Paddy and Water Environment》2013,11(1-4):331-341
A water balance model for paddy is developed primarily based on the principle of conservation of mass of soil–water within the root zone. The water balance for paddy is different from that of field crops because paddy requires standing water in the field during most of its growth period. This model requires soil, crop and meteorological data as inputs. This user friendly model was developed using computer programmes C and Visual Basic (VB) 6.0. It simulates various water balance components such as evapotranspiration, deep percolation, surface runoff and depth of irrigation water and ponding depth in the field on a daily basis. For estimation of deep percolation loss, physically based saturated and unsaturated flow processes are incorporated into the model to consider ponding (if there is standing water in the field), saturation (if moisture content of soil is in between field capacity and saturation) and depletion (if moisture content of soil is below field capacity) phases of paddy field. This article presents development of a user friendly water balance model for paddy and also its validation using published data. 相似文献
7.
Antifungal activity of Agapanthus africanus extractives 总被引：1，自引：0，他引：1
The ethanolic extract of the rhizomes of Agapanthus africanus showed antifungal activity. In bioassay guided fractionation, n-butanol fraction exhibited significant activity against human pathogens. A saponin, (25R)-spirost-7-en-2alpha,3beta,5alpha-triol-3-O-[alpha-L-rhamnopyranosyl(1-->2)-[beta-D-galactopyranosyl (1-->3)] beta-D-glucopyranoside (1), responsible for the antifungal activity and having MIC value of 15.6 microg/ml against Trychophyton mentagrophytes and Sporothrix schenekii, was isolated and identified as active constituent of the plant. 相似文献
8.
Damodhara R. Mailapalli N. S. Raghuwanshi R. Singh G. H. Schmitz F. Lennartz 《Irrigation Science》2008,26(2):161-168
TDR was used to estimate furrow infiltration, which is a key component in furrow irrigation system design and management.
Furrow irrigation experiments were conducted on bare and cropped fields consisting of three 40 m long parabolic shaped furrows
spaced at 0.8 m on a slope of 0.5%. The centre furrow was taken as the study furrow and the other two provided a buffer to
the centre furrow. Altogether, 22 irrigations were conducted during 2004 and 2005 with inflow rates ranging from 0.1 to 0.7 l s−1. TDR probes were installed vertically around the centre furrow at four locations 0.5 (S1), 13 (S2), 26 (S3) and 39.5 m (S4) from the inlet end. The S1 and S3 locations had four TDR probes installed at 0.15, 0.30, 0.45 and 0.60 m depths whereas the S2 and S4 locations had two probes each at 0.15 and 0.30 m depths. Soil moisture data collected at 5-min intervals were used to determine
the average soil moisture content of the field. The change in moisture content was used to estimate the furrow infiltration
which was compared with that measured using an inflow–outflow (IO) method. The performance of the TDR method was studied by
calculating the absolute prediction error (APE), root mean square error (RMSE) and index of agreement (I
a). It was found that the TDR-method estimated furrow infiltration well for higher inflow rates and during the initial stages
of irrigation. APE decreased and I
a increased with increase in flow rate for both bare and cropped conditions. The APE and RMSE were found to be larger for a
cropped field than the bare field when irrigated at the same inflow rate. The accuracy of the TDR-method for estimating total
infiltration was improved by using the average field moisture content of 30 or 45 min after the recession phase ceased. These
results indicate that TDR can be used to estimate in situ infiltration under furrow irrigation. 相似文献
9.
Furrow irrigation can be better managed if the management decision variables (irrigation time and amount; inflow rate and
cutoff) can be determined ahead of time. In this study, these decision variables were forecast and optimized using 1 day ahead
grass reference crop evapotranspiration (ET0) forecasts, based on the ARMA (1,1) time-series model, with a seasonal furrow irrigation model for both homogeneous and heterogeneous
infiltration conditions. Heterogeneity in infiltration characteristics was restricted to variations along the furrow length
as opposed to variations between furrows. The results obtained were compared with their counterparts using the observed ET0 for the same period during the 1992 cropping season. Seasonal performance (application efficiency, inflow, runoff and deep
percolation volumes) and economic return to water (yield benefits minus seasonal water related and labor costs) were affected
by infiltration conditions, while irrigation requirement and bean yield were unchanged. In a given infiltration case, seasonal
performance, irrigation schedules, bean yield and economic return to water were comparable (lower than 4% difference) for
the two ET0 conditions. For each ET0 condition, individual irrigation events resulted in different irrigation designs (inflow rate and cutoff time) except inflow
rates with heterogeneous infiltration. Differences in inflow volume were less than 2% and 5%, respectively, for homogeneous
infiltration and heterogeneous infiltration. For the conditions studied, furrow irrigation management decision variables can
be forecast and optimized to better manage the irrigation system, because irrigation performance was the same for both (forecast
and observed) ET0 cases.
Received: 9 October 1999 相似文献
10.
The use of artificial neural networks (ANNs) in estimation of evapotranspiration has received enormous interest in the present
decade. Several methodologies have been reported in the literature to realize the ANN modeling of evapotranspiration process.
The present review discusses these methodologies including ANN architecture development, selection of training algorithm,
and performance criteria. The paper also discusses the future research needs in ANN modeling of evapotranspiration to establish
this methodology as an alternative to the existing methods of evapotranspiration estimation. 相似文献