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1
Ahern, CR. "Comparison of models for predicting available water capacity of burdekin soils Queensland." Soil Research 26, no. 2 (1988): 409. http://dx.doi.org/10.1071/sr9880409.
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Various models for predicting profile available water capacity (PAWC) from laboratory measurements were compared with published field values for the same sites. The intention was to choose the best model/s to predict PAWC, by using a database, for a wide range of soils in the Burdekin Irrigation Area, North Queensland. Effective rooting depth for all models was estimated from the chloride profile. It was found that the predictive abilities of all models used were dependent on soil types. A conventional model (ASWC) based on the difference between water retained at -33 and -1500 kPa matric potentials was higher (P < 0.01) than field measured PAWC. An empirical model (PAWC2) based on cation exchange capacity (CEC) and depth was suitable only for cracking clays and sodic duplex soils. Another empirical model (PAWC1) based on -1500 kPa water retained and depth, predicted field PAWC particularly well on cracking clays, sodic duplex and related soils. There were strong indications that the PAWC1 model is also suitable for the better drained, lighter textured soils but there was a shortage of comparable field data to confirm this. The practical implication of these findings was that an analytical database can be used to predict PAWC on many Burdekin soils, providing immediate assistance to those designing irrigation channels and farm layouts.
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Tang, Xin De, Long Cheng Gao, and Nian Feng Han. "Effect of Spacer Length on the Liquid Crystalline Property of Azobenzene-Containing ABA-Type Triblock Copolymers via ATRP." Key Engineering Materials 428-429 (January 2010): 67–70. http://dx.doi.org/10.4028/www.scientific.net/kem.428-429.67.
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The effect of flexible spacer length on the liquid crystalline property of ABA-type triblock copolymers containing azobenzene groups was investigated. For the study, the monomers, n-[4-(4-ethoxyphenylazo)phenoxy]alkyl methacrylates with varying methylene groups (n = 0, 2, 6) were used to synthesize a series of azobenzene-containing amphiphilic triblock copolymers PAnC-PEG-PAnC by atom transfer radical polymerization (ATRP). Differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and one-dimensional X-ray diffraction (1D WAXD) have shown that the glass transition temperatures of these copolymers decreased as n increases. PA0C-PEG-PA0C has no mesophase, while both PA2C-PEG-PA2C and PA6C-PEG-PA6C have a nematic mesophase. These differences derive of the length of spacer groups between the polymer main chain and side chain.
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Prihandoko, Lastika Ary, Ana Shohibul Manshur Al Ahmad, Fredy Fredy, and Fathu Rahman. "Multi-Regression Analysis of Factors Influencing Perceived Academic Writing Competence (PAWC) of Vocational School Students." OKARA: Jurnal Bahasa dan Sastra 16, no. 2 (November 25, 2022): 329–48. http://dx.doi.org/10.19105/ojbs.v16i2.6928.
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Most upper-semester students who fail to graduate have an issue with their perceived academic writing competence (PAWC). PAWC is associated with writing self-efficacy (WSE) and writer's block (WB). Thus, improving WSE and decreasing WB are crucial for succeeding in the final project writing of the upper-semester students. Only limited studies focused on exploring academic writing practice for vocational students by survey strategy. This study used a quantitative approach to test the hypothesis that WSE and WB positively affect PAWC. Respondents were selected using random sampling involving 200 students from a vocational school in Surakarta. Respondents filled survey about PAWC, WSE, and WB consisting of 18 items. The hypothesis was tested by multiple regression analysis. The study results revealed that WSE and WB are positively correlated with PAWC. This research implies that faculty members are advised to focus on encouraging WSE and reducing WB to improve AW competence through curriculum improvements. With the increase in students' academic writing skills, the classic problem of late completion of studies due to late writing of the final project can be solved.
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Reynolds, W. D., X. M. Yang, C. F. Drury, T. Q. Zhang, and C. S. Tan. "Effects of selected conditioners and tillage on the physical quality of a clay loam soil." Canadian Journal of Soil Science 83, no. 4 (August 1, 2003): 381–93. http://dx.doi.org/10.4141/s02-066.
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Field-crop yields are below their genetic and climatic potentials on many fine-textured soils due to low organic carbon content (OC), high bulk density (ρb), low hydraulic conductivity (Ks), insufficient air capacity (AC) and low plant-available water capacity (PAWC). Although soil conditioners derived from municipal, agricultural and industrial wastes are frequently used to improve soils, their effects on overall soil physical quality are still poorly understood. Hence, the objective of this laboratory soil core study was to determine for a Brookston clay loam the effectiveness of masonry sand, greenhouse rockwool waste, yard waste compost and swine manure compost for improving soil physical quality relative to “ideal” levels proposed in the literature, and relative to “benchmark” levels found in the soil under virgin conditions, long-term conventional tillage and long-term no-tillage. The virgin soil produced near-surface (0.05–0.15 m depth) values for ρb(0.88 Mg m-3), AC (0.19 m3m-3) and PAWC (0.22 m3m-3) that fell within the optimal ranges proposed in the literature, while OC (68.2 g C kg-1) was slightly above optimal. The soil under long-term conventional tillage and no-tillage (cornsoybean rotation) produced below-optimal organic carbon content (21.9–22.5 g C kg-1), excessive ρb (1.45–1.47 Mg m-3), insufficient AC (0.06 m3m-3) and low PAWC (0.14–0.19 m3m-3). Conventional tillage also produced below-optimal Ks (10−6 m s-1). Each conditioner could improve one or more of the above parameters, but not all five. Adding sand at 20–100 wt. % improved AC, but caused excessive reductions in OC and PAWC, and excessive increases in ρb and Ks. Greenhouse rockwool waste added at 2.5–10 wt. % improved AC and ρb, but did not improve OC and PAWC. Yard waste compost added at 3.8–20 wt. % improved OC, ρb and PAWC, but did not improve AC. Adding swine manure compost at 3.8–20 wt. % improved OC and ρb, but did not improve AC or PAWC, and decreased Ks. As no single conditioner could optimize all soil physical quality parameters, future studies using combinations of conditioners are proposed. Key words: Soil physical quality, tillage, soil conditioners, clay loam, sand, rockwool, compos
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Rab, M. A., P. D. Fisher, R. D. Armstrong, M. Abuzar, N. J. Robinson, and S. Chandra. "Advances in precision agriculture in south-eastern Australia. IV. Spatial variability in plant-available water capacity of soil and its relationship with yield in site-specific management zones." Crop and Pasture Science 60, no. 9 (2009): 885. http://dx.doi.org/10.1071/cp08350.
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Spatial variability in grain yield can arise from variation in many different soil and terrain properties. Identification of important sources of variation that bear significant relationship with grain yield can help achieve more effective site-specific management. This study had three aims: (i) a geostatistical description/modelling of the paddock-level spatial structure in variability of plant-available water capacity (PAWC) and related soil properties, (ii) to determine optimal number of management zones in the paddock, and (iii) to assess if the variability in PAWC and related soil properties is significantly associated with the variability in grain yield across the management zones. Particle size distribution, bulk density (BD), field capacity (FC), permanent wilting point (PWP), and soil water content (SWC) at sowing were measured at 4 soil depths (to 0.60 m) at 50 representative spatial sampling locations across a paddock near Birchip (Victoria). PAWC and plant-available water at sowing (PAWs) were derived from these data. Moderate to strong spatial dependence across the paddock was observed. The magnitude of the structural variation and of range varied widely across different soil properties and depths. The south-east edge and the central areas of the paddock had higher clay content, FC, PWP, PAWC, and lower PAWs. The paddock was divided into 6 potential management zones using combined header yield and normalised difference vegetation index (NDVI). The adequacy of zoning was evaluated using relative variability (RV) of header yield and soil properties. The mean RV for 3 zones differed little from that of 6 management zones for header yield and for each measured soil property, indicating division of the paddock into 3 zones to be adequate. The results from residual maximum likelihood (ReML) analysis showed that low yield zones had significantly higher clay content, FC, PWP, SWC, and PAWC and significantly lower PAWs than both medium and high yield zones. The mean FC, PWP, and PAWC in the low yield zones were, respectively, 25%, 26%, and 28% higher, and PAWs 36% lower than their corresponding values in the high yield zones. Linear regression analysis indicated that 59–96% of the observed variation in grain yield across management zones could be explained by variation in PWP. The practical implications of these results are discussed.
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Oliver, Y. M., and M. J. Robertson. "Quantifying the benefits of accounting for yield potential in spatially and seasonally responsive nutrient management in a Mediterranean climate." Soil Research 47, no. 1 (2009): 114. http://dx.doi.org/10.1071/sr08099.
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Crop yield potential is a chief determinant of nutrient requirements, but there is little objective information available on the gains in profitability that can be made by accounting for the influences of soil type and season on yield potential when making fertiliser decisions. We conducted such an assessment using crop growth simulation coupled to nutrient response curves for wheat-growing at 4 locations in the low-medium rainfall zone of Western Australia. At each location, the yield potential was simulated on 10 soil types with plant-available water capacity (PAWC) ranging from 34 to 134 mm, which represent the major soils types in Western Australia. Soil survey maps were available to quantify soil type variability and the historical climate record (1974–2005) for seasonal variability. The benefits possible for fertiliser (NPK) management that takes account of variation in crop yield potential due to season and soil type by having ‘perfect knowledge’ ranged from $2 to 40/ha. Seasonal variation was more important than soil type for the better soils (high PAWC), providing two-thirds of the benefit of perfect knowledge. On low PAWC soils, knowledge of soils and seasonal influences on yield potential were similar contributors to profit gains. An assessment of one yield forecasting system showed that about 50% of the maximum gains could be captured if seasons could be categorised as below, at, or above average at the time the fertiliser decision is made. In each catchment, 30–40% of fields showed scope for benefits in accounting for within-field variation in soil type due to large variation in PAWC, and therefore yield. Maximum profit gains and reductions in nutrient excess were greater in the low rainfall locations and also on the low PAWC soil types.
7
Hochman, Z., N. P. Dalgliesh, and K. Bell. "Contributions of soil and crop factors to plant available soil water capacity of annual crops on Black and Grey Vertosols." Australian Journal of Agricultural Research 52, no. 10 (2001): 955. http://dx.doi.org/10.1071/ar01004.
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Improved methods for field measurements of plant available soil water capacity (PAWC) of Black and Grey Vertosols in Australia’s north-eastern grain region were employed to characterise 83 soil–crop combinations over 7 depth intervals to 180 cm. Soil sub-order was shown to influence all components of PAWC (means of 224 and 182 mm in Black and Grey Vertosols, respectively) with drained upper limit (DUL), bulk density (BD), and crop lower limits (CLL) showing clear separation between soil sub-orders and a trend with soil depth. In addition to soil sub-order and soil depth effects, CLL showed crop effects such that expected PAWC of various crops when adjusted for soil sub-orders were: cotton 240 mm; wheat 233 mm; sorghum 225 mm; fababean 209 mm; chickpea 197 mm; barley 191 mm; and mungbean 130 mm. A total of 549 measured CLL values were used to develop a predictive model for estimating CLL from the soil sub-order, depth, DUL, and crop by predicting a CLL as a function of DUL and a depth-dependent variable for each crop–soil sub-order. The model CLL = DUL * (a + b * DUL) explained 85% of observed variation in the measured data with no significant bias between observed and predicted data. While properly measured data would be more reliable than estimated data, where specific site accuracy is less critical, this model may be used to estimate PAWC with an acceptable degree of accuracy.
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Hermawan, Bandi, Hasanudin Hasaanudin, Indra Agustian, and Bambang Gonggo Murcitro. "A Model to Predict Plant-available Water Content of Soils at Different Land Units in Bengkulu, Indonesia." TERRA : Journal of Land Restoration 3, no. 1 (June 19, 2020): 10–14. http://dx.doi.org/10.31186/terra.3.1.10-14.
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Soil water availability to the plants is a very important physical property of soil that controls water and nutrient absorption by the plant. It is defined as the difference between the maximum amount of water the soil can hold and the minimum condition that the plant can no longer extract water from the soil. However, soil factors that control the plant available water content (PAWC) in the soil have not been fully understood. The present study aims to analyze the relations between particle-size distributions and organic carbon with the available water of the soil and to develop a model of predicting PAWC. Five soil profiles at different land units were described up to the depth of 100 cm. Ten undisturbed soil samples were taken using the stainless-made core sampler from 10 cm increments for the soil water holding capacity analysis. A similar number of disturbed samples were also provided from the same depths for soil texture and organic carbon analysis. Results showed that the variance in PAWC could be explained by sand and clay fractions (R2>0.35) but not by silt and organic carbon contents. Therefore, we were able to develop a model for the prediction of available water content in the soil from the sand and clay parameters. The model will help decision-makers be able to propose conservation and management strategies for PAWC in agricultural practices as well as for the soil moisture retention at civil works.
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Robinson, J. B., D. M. Silburn, D. Rattray, D. M. Freebairn, A. Biggs, D. McClymont, and N. Christodoulou. "Modelling shows that the high rates of deep drainage in parts of the Goondoola Basin in semi-arid Queensland can be reduced with changes to the farming systems." Soil Research 48, no. 1 (2010): 58. http://dx.doi.org/10.1071/sr09067.
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Clearing native vegetation and introducing crops and pastures may increase deep drainage and result in dryland salinity. In south-west Queensland, native vegetation of the Goondoola Basin has been substantially cleared for cropping and pastoral activities, resulting in shallow groundwater and localised salinity. Simulation modelling was used to estimate the water balance of a range of vegetation and soil types. Six soils were studied, with plant-available water capacity (PAWC) of 71 mm (a Kandosol) to 198 mm (a Vertosol) for 1200 mm depth. Vegetation types were annual wheat, opportunity cropping, and perennial pastures in poor and good condition, and high quality perennial pasture with deep roots growing on deep (2400 mm) variants of the 6 soil types. Opportunity cropping did not reduce deep drainage. Substantial differences were found in long-term average deep drainage (mm/year) between wheat crops and pastures for all soil types. The differences in deep drainage between wheat cropping and pasture in good condition were greatest for the 2 Kandosols, which had the lowest PAWC (34 and 21 mm/year less deep drainage, reductions of 53% and 62%, respectively), and a Vertosol with intermediate PAWC (23 mm/year less deep drainage). A Chromosol and a Dermosol with intermediate PAWC had smaller reductions in deep drainage (14 and 11 mm/year, respectively). In the case of a Vertosol with high PAWC (198 mm), deep drainage was negligible with all pastures. Due to increased infiltration and reduced soil evaporation, more deep drainage was simulated with pasture in good condition than pastures in poor condition, especially for 2 Kandosols. Pasture with deep roots (2400 mm) growing on deep variants (2400 mm) of the 6 soils had lower rates of deep drainage than the other pastures. Simulated deep drainage and other components of the water balance were in good agreement with field measurements and expectations. These results indicate that large reductions in deep drainage can be achieved in the Goondoola Basin by replacing cropping with pastoral activities. Kandosol soils used for wheat cropping should be the primary target for land use change.
10
Dolling, P. J., R. A. Latta, P. R. Ward, M. J. Robertson, and S. Asseng. "Soil water extraction and biomass production by lucerne in the south of Western Australia." Australian Journal of Agricultural Research 56, no. 4 (2005): 389. http://dx.doi.org/10.1071/ar04158.
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To understand the factors involved in lucerne reducing drainage below the root-zone and influencing lucerne biomass production and water extraction were analysed in the south of Western Australia. The lucerne was grown for 3 years before removal. The factors investigated as part of the water extraction analysis included the rate of advance of the extraction front or extraction front velocity (EFV, mm/day), the soil plant-available water-holding capacity (PAWC, mm/m soil), and the temporal change in soil water deficit (drainage buffer, mm). The drainage buffer is related to the EFV and PAWC. A site with deep sand had the highest EFV (mean of 9.2 mm/day) but the lowest PAWC (mean of 32 mm/m soil) to a depth of 4 m. In the duplex soils the EFV was 18–34% of the deep sand EFV and the PAWC was 60–222% higher than the deep sand PAWC to a depth of 1.6–2.1 m. The EFV was reduced by the higher clay content and sodicity in the B horizon of the duplex soils. The highest drainage buffer measurements occurred in the deep sand site and the better structured duplex soils and therefore these soils will have the greater effect on reducing drainage below the root-zone. However, lucerne was able to create a drainage buffer to at least a depth of 1.5 m over 3 years and therefore contribute to a reduced drainage even on the most sodic and saline sites. Low soil pH did not affect the drainage buffer as much as soil texture and structure. Variation in biomass production of lucerne-based pastures was positively related to rainfall and water use (taking into account soil water storage and drainage losses) across sites, explaining approximately 50% of the biomass variation. Rainfall and water use could therefore be used for predicting lucerne biomass production in Western Australia. Biomass water use efficiency was highest in spring (15 kg/ha.mm) and least during autumn (4.5 kg/ha.mm).
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Dolling, P. J., R. A. Latta, P. R. Ward, M. J. Robertson, and S. Asseng. "Corrigendum to: Soil water extraction and biomass production by lucerne in the south of Western Australia." Australian Journal of Agricultural Research 56, no. 9 (2005): 1010. http://dx.doi.org/10.1071/ar04158_co.
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To understand the factors involved in lucerne reducing drainage below the root-zone and influencing lucerne biomass production and water extraction were analysed in the south of Western Australia. The lucerne was grown for 3 years before removal. The factors investigated as part of the water extraction analysis included the rate of advance of the extraction front or extraction front velocity (EFV, mm/day), the soil plant-available water-holding capacity (PAWC, mm/m soil), and the temporal change in soil water deficit (drainage buffer, mm). The drainage buffer is related to the EFV and PAWC. A site with deep sand had the highest EFV (mean of 9.2�mm/day) but the lowest PAWC (mean of 32�mm/m soil) to a depth of 4�m. In the duplex soils the EFV was 18.34% of the deep sand EFV and the PAWC was 60.222% higher than the deep sand PAWC to a depth of 1.6.2.1�m. The EFV was reduced by the higher clay content and sodicity in the B horizon of the duplex soils. The highest drainage buffer measurements occurred in the deep sand site and the better structured duplex soils and therefore these soils will have the greater effect on reducing drainage below the root-zone. However, lucerne was able to create a drainage buffer to at least a depth of 1.5�m over 3 years and therefore contribute to a reduced drainage even on the most sodic and saline sites. Low soil pH did not affect the drainage buffer as much as soil texture and structure. Variation in biomass production of lucerne-based pastures was positively related to rainfall and water use (taking into account soil water storage and drainage losses) across sites, explaining approximately 50% of the biomass variation. Rainfall and water use could therefore be used for predicting lucerne biomass production in Western Australia. Biomass water use efficiency was highest in spring (15 kg/ha.mm) and least during autumn (4.5 kg/ha.mm).
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WHISH, J. P. M., P. CASTOR, P. S. CARBERRY, and A. S. PEAKE. "ON-FARM ASSESSMENT OF CONSTRAINTS TO CHICKPEA (CICER ARIETINUM) PRODUCTION IN MARGINAL AREAS OF NORTHERN AUSTRALIA." Experimental Agriculture 43, no. 4 (October 2007): 505–20. http://dx.doi.org/10.1017/s0014479707005297.
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Chickpea production in marginal (<600 mm annual rainfall) areas of the northern cropping region in eastern Australia is considered to be constrained by low rainfall, soils with low plant available water capacity (PAWC), subsoil salinity, low plant stature and poor fruit set. This study examines these constraints to assess the magnitude of their impact and if agronomic practices can improve potential production. Over three years a total of 42 commercial chickpea crops were monitored following a participatory action research approach focusing on perceived production constraints. Subsoil salinity significantly reduced PAWC for chickpea compared to wheat. However, PAWC for chickpeas from the majority of sites monitored was comparable to other areas. The supply of water between flowering and maturity was significantly related to yield. The agronomic practice of levelling following deep planting improved the lowest pod height by 10 cm and plant stresses experienced during flowering caused a 50 % loss of potential fruit. Constraints impacting on the supply and storage of soil water could be minimized by selecting paddocks with low chloride levels in the upper layers and sowing crops when the available soil water is greater than 100 mm. Reducing fruit loss at flowering has the potential to improve yields significantly. The mechanisms behind this loss were not identified but are worthy of further research.
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Peake, A. S., M. J. Robertson, and R. J. Bidstrup. "Optimising maize plant population and irrigation strategies on the Darling Downs using the APSIM crop simulation model." Australian Journal of Experimental Agriculture 48, no. 3 (2008): 313. http://dx.doi.org/10.1071/ea06108.
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Optimum plant population and irrigation strategies for maize grown in the Dalby district of the Darling Downs in Queensland, Australia, were investigated using the APSIM crop simulation model. After testing the model against three seasons of experimental data, simulation experiments using different irrigation strategies were conducted across a range of plant populations ranging from 20 000 to 80 000 plants/ha, on two soil types with plant available water capacities (PAWC) of 146 mm and 220 mm. All soil type × plant population × irrigation strategy scenarios were simulated using the historical climate record for Dalby from 1889 to 2004, in order to obtain long-term average yield and gross margins (LGM) for each scenario. Soil water was reset to two-thirds of PAWC at sowing in each year. Plant populations required to achieve maximum LGMs ranged from 50 000 to 80 000 plants/ha across the range of scenarios, and were higher than currently recommended by district agronomists for partially irrigated maize. The use of higher plant populations increased season-to-season variability in grain yield and gross margins and may not be a suitable strategy for growers who do not want to increase their risk of crop failure. Partially irrigated maize achieved substantially higher gross margins in years where a positive Southern Oscillation Index phase was recorded in August, and the use of higher plant populations in such years also increased long-term profitability, but also increased the risk of crop failure. Economic gains were achieved by varying the timing and amount of irrigation within a limited available irrigation volume, with a single 100 mm irrigation giving greater LGMs than two 50 mm irrigation events on both soil types, when the irrigation events were scheduled to fill a soil water deficit equal to the effective irrigation volume. However, under full irrigation the use of smaller irrigation volumes increased LGMs on the 146 mm PAWC soil, demonstrating the importance of timely irrigation scheduling on low PAWC soils.
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Oliver, Y. M., M. J. Robertson, P. J. Stone, and A. Whitbread. "Improving estimates of water-limited yield of wheat by accounting for soil type and within-season rainfall." Crop and Pasture Science 60, no. 12 (2009): 1137. http://dx.doi.org/10.1071/cp09122.
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Rainfall is the main driver of potential yield in the dryland cropping environment of Australia. Rainfall-based empirically derived models such as that proposed by French and Schultz (1984) (F&S) can be used to determine an upper limit of water-limited potential yield, but F&S often overestimates actual yield as it does not account for rainfall distribution, runoff, drainage, or stored soil water. More complex models are available to predict potential yield more accurately; however, farmers and advisors favour easy-to-use-methods to estimate potential yield. To derive a simple yet accurate method for estimating potential yield, several adjustments to F&S were evaluated: (1) accounting for stored soil water at sowing, (2) varying the value of the intercept between yield and growing-season rainfall (GSR), (3) varying the water-use efficiency of the crops (WUE) according to soil type, and (4) adjustments to GSR depending on soil plant-available water capacity (PAWC). The water-limited potential yields predicted from these methods were compared with simulations from the daily time-step simulation model APSIM and observed wheat yields from 146 dryland wheat crops, managed to water-limited potential yield, covering the 1996–2006 seasons in the Mediterranean-type growing environments of Australia. The original F&S method overestimated actual yields, particularly at high rainfall (GSR > 220 mm) when PAWC was low, and underestimated yields at low rainfall (GSR < 220 mm). Significant improvements to the F&S were achieved with a few simple adjustments. With the addition of a variable intercept (dependent upon GSR), accounting for stored soil water at the start of the season and placing a cap on GSR that is a function of the soil PAWC, the predictive performance (RMSE 624 kg/ha) was similar to that gained with the daily time-step model APSIM (RMSE 419 kg/ha). The improved method gave more realistic estimates of water-limited potential yield, particularly at low and high rainfall and on soils of low PAWC.
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Reynolds, W. D., C. F. Drury, C. S. Tan, and X. M. Yang. "Temporal effects of food waste compost on soil physical quality and productivity." Canadian Journal of Soil Science 95, no. 3 (August 2015): 251–68. http://dx.doi.org/10.4141/cjss-2014-114.
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Reynolds, W. D., Drury, C. F., Tan, C. S. and Yang, X. M. 2015. Temporal effects of food waste compost on soil physical quality and productivity. Can. J. Soil Sci. 95: 251–268. The benefits of compost additions on soil organic carbon content and crop productivity are extant in the literature, but detailed studies of compost effects on soil physical quality (SPQ) are limited. The objective of this study was therefore to describe how one-time additions of compost impact the immediate, mid-term and long-term SPQ and crop yields of an agricultural soil. Food waste compost (FWC) was incorporated once into the top 10 cm of a humid-temperate Brookston clay loam soil at rates of 0 (Control), 75 dry t ha−1 (FWC-75), 150 dry t ha−1 (FWC–150) and 300 dry t ha−1 (FWC-300); measurements of SPQ parameters and corn yield were then made annually over the next 11 yr. The SPQ parameters included bulk density (BD), organic carbon content (OC), air capacity (AC), plant-available water capacity (PAWC), relative field capacity (RFC), and saturated hydraulic conductivity (KS), which were obtained from intact (undisturbed) soil core samples. Prior to compost addition, BD, OC, AC, PAWC, RFC and KS were substantially non-optimal, and BD had increased relative to virgin soil by 46%, while OC, AC and PAWC had decreased relative to virgin soil by 60, 56 and 43%, respectively. Improvements in SPQ 1 yr after compost addition were negligible or small for FWC-75 and FWC-150, but FWC-300 generated optimal values for BD, OC, AC, PAWC and RFC. The SPQ parameters degraded with time, but 11 yr after compost addition, OC and AC under FWC-300 were still within their optimal ranges, as well as significantly (P<0.05) greater than the Control values by 65 and 26%, respectively. Soil cracks and biopores apparently induced substantial annual variation in KS, but average KS nevertheless increased with increasing compost addition rate. Corn grain yield varied substantially among years, which was likely due to weather and compost effects; however, 11-yr cumulative yields from the compost treatments were greater than the Control by 2200–6500 kg ha−1.
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Reynolds, W. D., C. F. Drury, X. M. Yang, C. S. Tan, and J. Y. Yang. "Impacts of 48 years of consistent cropping, fertilization and land management on the physical quality of a clay loam soil." Canadian Journal of Soil Science 94, no. 3 (August 2014): 403–19. http://dx.doi.org/10.4141/cjss2013-097.
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Reynolds, W. D., Drury, C. F., Yang, X. M., Tan, C. S. and Yang, J. Y. 2014. Impacts of 48 years of consistent cropping, fertilization and land management on the physical quality of a clay loam soil. Can. J. Soil Sci. 94: 403–419. Soil physical quality (SPQ) is often ignored or under-monitored in long-term field studies designed to determine the economic and environmental sustainability of agricultural practices. Accordingly, a suite of complementary soil physical and hydraulic parameters was measured using intact core samples to determine the SPQ of a Brookston clay loam under a long-term (48 yr) cropping, fertilization and land management study at Woodslee, Ontario. The SPQ under virgin woodlot, fertilized monoculture sod and unfertilized monoculture sod treatments was similar, with optimal SPQ occurring in the top 10–20 cm, but severely suboptimal SPQ occurring below 30 cm because bulk density (BD), relative field capacity (RFC) and saturated hydraulic conductivity (KS) were excessive, and because organic carbon (OC), air capacity (AC) and plant-available water capacity (PAWC) were critically low. The SPQ for fertilized and unfertilized monoculture corn under fall moldboard plow tillage was similar and substantially suboptimal throughout the top 40–50 cm due to high or excessive BD and RFC, critically low OC, low or critically low AC and PAWC, and KSthat varied erratically from excessive to critically low. The SPQ under fertilized and unfertilized corn–oat–alfalfa–alfalfa rotations (corn and second-year alfalfa fall plowed) was similar and largely non-optimal below 10 cm, but largely optimal in the top 10 cm due to the ameliorating effects of numerous biopores and crop roots. A bimodal soil water release function fitted to release curve data showed that PAWC was determined by soil matrix porosity (PM), and AC was determined by soil structure porosity (PS). Strong inverse linear correlations between BD vs. PM, BD vs. PSand BD vs. OC provided site-specific estimates of optimal ranges and critical limits for PAWC, AC and OC, respectively. Although SPQ changed substantially among treatments, the changes did not extend below 30-to 40-cm depth, and were largely unaffected by long-term annual fertilization. The SPQ below 30- to 40-cm depth was similarly poor across all treatments, and is likely an inherent characteristic of the soil.
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CEULEMANS, R., I. IMPENS, M. C. LAKER, F. M. G. VAN ASSCHE, and R. MOTTRAM. "NET CO2 EXCHANGE RATE AS A SENSITIVE INDICATOR OF PLANT WATER STATUS IN CORN (Zea mays L.)." Canadian Journal of Plant Science 68, no. 3 (July 1, 1988): 597–606. http://dx.doi.org/10.4141/cjps88-072.
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With the objective to evaluate and compare different physiological plant parameters as indicators of water stress, net CO2 exchange rate (NCER), leaf temperature, predawn and daytime leaf water potential were monitored diurnally on last fully expanded leaves of corn (Zea mays L.) plants under two different soil water treatments (stressed and nonstressed) during a 10-d period at anthesis in a semi-arid region in South Africa. Profile available water capacity (PAWC) was used to express the soil water contents during the experiments. A significant decrease in NCER was noticed as soon as 30% of PAWC was extracted, i.e. 2 or 3 d after irrigation. Although the results were limited to a short, well-defined measuring period, NCER, and especially NCER at noon, seemed to be a more sensitive and more reliable indicator of corn water stress than, for example, predawn or daytime leaf water potential, at least under the conditions studied here. This reduction in NCER might have a significant impact on total biomass, rooting density, flower and ear formation.Key words: Corn, irrigation scheduling, photosynthesis, leaf water potential, profile available water capacity, soil water content
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., Agbai. "THE SHORT TERM EFFECT OF TILLAGE SYSTEM ON SOIL MOISTURE RETENTION IN BAYELSA STATE, NIGERIA." Journal of Wastes and Biomass Management 4, no. 1 (2022): 45–52. http://dx.doi.org/10.26480/jwbm.01.2022.45.52.
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The objective of the study was to determine the short time effect of tillage system on the water retention capacity of soils in the Niger Delta University Teaching and Research Farm, Bayelsa State. Five treatments (No-till, Digging, Hoeing, Hoeing+Digging once, and Hoeing+Digging twice) were considered. Plant Available Water Content (PAWC) and the Soil Water Holding Capacity (SWHC) were used to determine the soil water retention capacity. The results revealed that the crude tillage methods had a significant (P<0.05) impact on some soil properties. The highest bulk density (1.18g/cm3) was found in the No-till zone, while the lowest (0.89g/cm3) was in the Hoe+Digging twice method. The tillage methods also affected the hydraulic conductivity as the highest value (4.67cm/hr) was found in the hoe+digging zone and the lowest (2.61cm/hr) in the no-till area. Furthermore, the PAWC and SWHC were highest (0.14cm3cm-3 and 2.03cm) at the No-till zone and lowest (0.06 cm3cm-3 and 0.95cm) at the Hoe+Digging twice zone. It is therefore recommended that, for unrestricted flow of water through the soils, compacted soils should be pulverized using tillage implements. Also, for optimal plant water availability, there should be less tillage on coarse-textured soils, as the disturbance promotes rapid leaching.
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Agbai, W. P., and M. T. Kosuowei. "Influence of land-use systems on hydraulic properties of soils in Yenagoa and Amassoma, Bayelsa State, Nigeria." International Journal of Environment 11, no. 1 (June 20, 2022): 23–45. http://dx.doi.org/10.3126/ije.v11i1.45838.
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This research aimed to determine the effect of different land-use systems on the matric potential, and hydraulic conductivity of the soils of Yenagoa and Amassoma communities. Soil samples were collected from four respective land-use types namely: Fallow land, Oil Palm Plantation, Plantain Plantation, and Virgin land. A total of 12 samples were bulked from three replicates at each land use type and were collected at depths of 0-15cm, 15-30cm, and 30-45cm respectively. The samples were taken to the laboratory to analyze their physical, chemical, and hydrological properties. The result showed that the different land use had a significant effect (P<0.05) on some soil physical, chemical, and hydraulic characteristics. The different land-use systems had a significant effect on the soil hydraulic conductivity with the highest in virgin (13.6 cm/hr) and lowest in the plantain plantation (7.6 cm/hr). The virgin land recorded the highest Soil Water Holding Capacity (SWHC) of 2.85 cm with a range of 1.55 – 2.85cm and Plant Available Water Capacity (PAWC) of 0.19 cm3cm-3, with a range of 0.10 - 0.19 cm3cm-3, while the plantain plantation recorded the lowest (1.55 cm and 0.10 cm3cm3). Based on the study, it is recommended that soils with high Plant Available Water Capacity (PAWC) and Soil Water Holding Capacity (SWHC) be used to cultivate crops that are non-tolerant to water stress while organic amendments are used on soils with low fertility.
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Ockerby, SE, DJ Lyons, GD Keefer, FPC Blamey, and DF Yule. "Irrigation frequency and nitrogen fertilizers modify cotton yield at Emerald, central Queensland." Australian Journal of Agricultural Research 44, no. 6 (1993): 1389. http://dx.doi.org/10.1071/ar9931389.
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Four irrigation frequencies and six nitrogen (N) fertilizer rates (0-300 kg ha-1) were applied to cotton (Gossypium hirsutum L.) grown on three Vertisols in the Emerald Irrigation Area, central Queensland. The purpose was to describe lint production responses to the plant available water before irrigation and N fertilizer, in terms of the crop N content and the efficiency of crop N use for lint production. Lint yield was greatest when the plant available water before irrigation was 50-80010 of the plant available water capacity (PAWC) of each soil. The rate of N fertilizer for maximum yield varied with plant available water and soil type. Plant available water before irrigation >60% and <37% PAWC, and rain after irrigation reduced the crop N content at the time of maximum leaf area index. Relative yield generally responded to 130 kg crop N ha-', although the range from 101 to 141 kg crop N ha-1 reflected differences in the maximum yield of each treatment. If the crop N was <130 kg ha-1, yield was mostly determined by the crop N content, whereas if the crop N content was >130 kg ha-1, yield and the efficiency of crop N use for lint production was determined by the plant available water before irrigation and soil type. Nitrogen fertilizer strategies to achieve the maximum yield of cotton (var. Deltapine 61) should focus on obtaining 130 kg crop N ha-1. This crop N content produced maximum yields for a range of plant available water contents before irrigation, and for three soil types.
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Whitbread, Anthony M., Munir P. Hoffmann, C. William Davoren, Damian Mowat, and Jeffrey A. Baldock. "Measuring and Modeling the Water Balance in Low-Rainfall Cropping Systems." Transactions of the ASABE 60, no. 6 (2017): 2097–110. http://dx.doi.org/10.13031/trans.12581.
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Abstract. In low-rainfall cropping systems, understanding the water balance, and in particular the storage of soil water in the rooting zone for use by crops, is considered critical for devising risk management strategies for grain-based farming. Crop-soil modeling remains a cost-effective option for understanding the interactions between rainfall, soil, and crop growth, from which management options can be derived. The objective of this study was to assess the error in the prediction of soil water content at key decision points in the season against continuous, multi-layer soil water measurements made with frequency domain reflectometry (FDR) probes in long-term experiments in the Mallee region of South Australia and New South Wales. Field estimates of the crop lower limit or drained upper limit were found to be more reliable than laboratory-based estimates, despite the fact that plant-available water capacity (PAWC) did not substantially differ between the methods. Using the Agricultural Production Systems sIMulator (APSIM) to simulate plant-available water over three-year rotations, predicted soil water was within 7 mm (PAWC 64 to 99 mm) of the measured data across all sowing events and rotations. Simulated (n = 46) wheat grain production resulted in a root mean square error (RMSE) of 492 kg ha-1, which is only marginally smaller than that of other field studies that derived soil water limits with less detailed methods. This study shows that using field-derived data of soil water limits and soil-specific settings for parameterization of other properties that determine soil evaporation and water redistribution enables APSIM to be widely applied for managing climate risk in low-rainfall environments. Keywords: APSIM, Climate risk management, Crop models, Decision support, Soil moisture.
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Castellini, Mirko, Alessandro Vittorio Vonella, Domenico Ventrella, Michele Rinaldi, and Giorgio Baiamonte. "Determining Soil Hydraulic Properties Using Infiltrometer Techniques: An Assessment of Temporal Variability in a Long-Term Experiment under Minimum- and No-Tillage Soil Management." Sustainability 12, no. 12 (June 19, 2020): 5019. http://dx.doi.org/10.3390/su12125019.
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Conservation agriculture is increasingly accepted by farmers, but the modeling studies on agro-environmental processes that characterize these agricultural systems require accurate information on the temporal variability of the soil’s main physical and hydraulic properties. Therefore, specific investigations carried out in long-term experiments can increase our knowledge on the pros and cons of different measurement techniques. In this work, the simplified falling head (SFH) technique and the Beerkan Estimation of Soil Transfer (BEST) procedure were applied to investigate the temporal variability of some main soil physical and hydraulic properties, including bulk density (BD), field saturated hydraulic conductivity (Kfs), macroporosity (Pmac), air capacity (AC), plant available water capacity (PAWC), and relative field capacity (RFC). For this purpose, a long-term experiment was selected, and the experimental information obtained was used to verify the long-term impact (fifteen years) determined by two alternative forms of soil management, minimum tillage (MT) and no tillage (NT), for the cultivation of durum wheat. The main results of the comparison between MT and NT showed: (i) A comparable temporal variability in Kfs values when SFH was considered, given that in 75% of considered cases, the same result (i.e., significant or not significant) was obtained; (ii) a comparable temporal variability in Kfs values under MT (but not under NT) when both SFH and BEST were used, as a result of a possible Kfs,SFH overestimation under NT; (iii) differences in Kfs estimations by a factor of 6 or 7 (Kfs,SFH > Kfs,BEST) when comparable soil conditions (moisture and soil density) were considered; (iv) a comparable temporal variability when other soil indicators (BD, Pmac, AC, PAWC, and RFC) were simultaneously considered. After about fifteen years of field experiments characterized by continuous soil management and conducted with the methodological rigor typical of experimental farms, the SFH- and BEST-derived experimental information showed a substantial equivalence between MT and NT for the fine-textured soil investigated.
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Becker, Regiane Kazmierczak, Eduardo Augusto Agnellos Barbosa, Neyde Fabíola Balarezo Giarola, Edson Giovani Kochinski, Fabrício Pinheiro Povh, Ariane Lentice de Paula, and Maurício Roberto Cherubin. "Mechanical Intervention in Compacted No-Till Soil in Southern Brazil: Soil Physical Quality and Maize Yield." Agronomy 12, no. 10 (September 23, 2022): 2281. http://dx.doi.org/10.3390/agronomy12102281.
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The intense and successive use of mechanization in modern cropping systems has increased soil compaction under no-till areas. In this study, we aimed to assess the performance of a fixed shank coupled with a seeder for the mitigation of soil compaction induced by machinery traffic as an efficient alternative to replacing the chiseling and subsoiling operations in no-till areas. We evaluated a long-term experiment conducted in clay loam (Rhodic Haplustox) soil in southern Brazil. The experiment was conducted under a randomized block design, whose treatments consisted of three wheel-traffic intensities: 0 wheel-traffic (0 WT), 14 wheel-traffic (14 WT), and 28 wheel-traffic (28 WT), combined with four soil tillage mechanical interventions under a no-till field: no-till (NT), no-till with a fixed shank (NT + FS), soil chiseling (SC), and soil subsoiling (SS). The soil physical attributes evaluated were the soil penetration resistance (SPR), macroporosity (MaP), microporosity (MiP), total porosity (TP), bulk density (BD), field-saturated hydraulic conductivity (Kfs), S index, and plant-available water capacity (PAWC). In addition, three critical soil physical functions were evaluated by using a soil physical quality index (SPQI). The results showed that SPR was sensitive to soil compaction and captured differences among the mechanical intervention methods. Machinery traffic caused soil compaction, increasing SPR and reducing PAWC. Soil chiseling and subsoiling promoted lower BD, a higher TP, MaP, Kfs, and higher S index at the 0.05–0.15 m soil layer. Based on the SPQI, no changes were detected in the soil physical functions between NT and NT + FS. On the other hand, SC and SS enhanced soil physical functioning by 10%. We concluded that a 15-cm deep fixed shank could not mitigate the soil compaction induced by machinery traffic at the seeder operation. Therefore, this method is less effective in improving the soil’s physical environment than chiseling and subsoiling operations. Finally, we encourage monitoring the persistence of these benefits on the soil over the subsequent crop seasons and in years with an intense water deficit along with the crop cycle.
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Balog, Kitti, András Szabó, and János Rásó. "The impact of soil and climatic factors on forest growth." Review on Agriculture and Rural Development 5, no. 1-2 (January 1, 2016): 19–25. http://dx.doi.org/10.14232/rard.2016.1-2.19-25.
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This preliminary study reveals the relations between the forest growth (annual dendromass increment; ADMinc - as dependent variable) and some important soil factors, which have effect on plant growth, such as: groundwater level (GWL), groundwater composition (GWC), plant available water capacity (PAWC), depth of humus layer, texture (hyi) and pH of the soil, moreover the maximum concentration (MAX) of salt and CaCCb and the depth of its MAX in the soil profile. 17 plantations (Poplar, Common oak and Black locust) are included in the analysis investigated all over the Great Hungarian Plain. Correlation profile of the above parameters was created explaining that two abiotic parameters limit plant growth: if GWL is deeper than 5 m and if HCO3 concentration in groundwater is high (above 15 meq/L). Within the tested range (0.17 - 2.23 mS/cm for electrical conductivity (EC) and 0.5 /sand/ - 4.21 /clay loam/ for hyi), the higher magnitude of EC results in higher ADMinc and the higher hyi (higher proportion of fine soil particles) leads to higher ADMinc The positive relationship of ADMinc with EC suggests good nutrient supply of the soil, while the higher proportion of fine particles refers to better water management properties. Thickness of humus layer is an important soil factor: compared to shallow humus layer, deep one increases ADMinc exponentially. In case of Black locust, PAWC is the substantial factor for growing, unlike Poplar, whose growth depends on groundwater uptake (GWU). This phenomenon originates from the differences between the individual needs of the tree species and differences in root morphology. Merely 4 sampling plots were equipped with meteorological stations, thus the number of climatic parameter data were not enough for statistical analysis. So data for all 17 plots were collected from literature and a general, regionally calculated data were applied (mean rainfall in the vegetation period and aridity index). There was no significant correlation between climatic parameters and ADMinc Further studies and more field investigations are needed in order to clarify the results.
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Armstrong, R. D., K. McCosker, K. Walsh, G. Millar, B. Kuskopf, M. E. Probert, S. Johnson, and J. Standley. "Legume and opportunity cropping systems in central Queensland. 2. Effect of legumes on following crops." Australian Journal of Agricultural Research 50, no. 6 (1999): 925. http://dx.doi.org/10.1071/ar98101.
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Poor yields and low grain protein in cereal crops resulting from declining soil fertility, especially nitrogen (N), are major threats to the grains industry in central Queensland. The effect of 4 different pasture-ley legumes [siratro (Macroptilium atropurpureum cv. Siratro), lucerne (Medicago sativa cv. Trifecta), lablab (Lablab purpureus cv. Highworth), and desmanthus (Desmanthus virgatus cv. Marc)] on grain yield and quality of sorghum crops was compared with that of a pulse (mungbean; Vigna radiata cv. Satin) or continuous cropping with grain sorghum (Sorghum bicolor). Legume leys consistently resulted in large increases in grain yield (188–272%), N uptake by sorghum (145–345%), and grain protein (0.21–7.0% increase in grain protein) in sorghum test-crops compared with continuous sorghum crops to which no fertiliser N had been added. The positive effect of legumes persisted up to 3 sorghum test-crops after only 1 year of legumes, although by the third year the effect was comparatively small. Mungbean and lablab generally produced the largest benefit in sorghum test-crops in the first year after legumes, whereas desmanthus and lucerne produced the least benefit. Adding fertiliser N (up to 75 kg N/ha) significantly improved grain yields and N uptake of sorghum test-crops in 3 of 4 years. However, responses to fertilisers were less than those resulting from legumes, which was ascribed to increased availability of legume N to sorghum. Legumes progressively increased soil nitrate in all subsequent sorghum test-crops (compared with continuous sorghum crops), rising from 6.8–18.9 kg NO3-N/ha after 1 year of legumes to 24.2–59.6 kg NO3-N/ha after 3 years of legumes. There was little difference between the legumes in their ability to increase soil nitrate, with the exception of desmanthus, which consistently resulted in the lowest amount of soil nitrate for subsequent test-crops and lowest uptake of N by these crops. Plant-available water content (PAWC) at planting of the sorghum test-crop was only significantly (P<0.05) affected by previous species in 1997, when it was lowest in plots previously sown to siratro and lucerne and highest in sorghum and mungbean plots. In both 1996 and 1997, plots sown to sorghum had significantly higher PAWC at anthesis and grain maturity when previous plots were sorghum rather than legumes.
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He, Di, Yvette Oliver, Abdur Rab, Peter Fisher, Roger Armstrong, Matt Kitching, and Enli Wang. "Plant available water capacity (PAWC) of soils predicted from crop yields better reflects within-field soil physicochemical variations." Geoderma 422 (September 2022): 115958. http://dx.doi.org/10.1016/j.geoderma.2022.115958.
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Zade, S. P., P. H. Vaidya, P. R. Kadu, and P. Tiwary. "Plant Available Water Capacity (PAWC) for Deep-Rooted Crops in Cracking Clay Soils (Vertisols) of Semi-Arid Central India." Clay Research 39, no. 2 (2020): 89–109. http://dx.doi.org/10.5958/0974-4509.2020.00010.8.
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Zhang, Qiufen, Jiakai Liu, Lihua Chen, and Xinxiao Yu. "The quantitative analysis of the influence of environmental factors on the water yield capacity: a study in Haihe river basin, China." Journal of Water and Climate Change 11, no. 4 (April 30, 2019): 1203–17. http://dx.doi.org/10.2166/wcc.2019.285.
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Abstract Many studies have qualitatively analyzed the response of hydrological characteristics to climate change in Haihe river basin, but quantitative research has been rare, which is essential for water resource management. To evaluate and quantitatively analyze the relationship between catchment runoff capacity and environmental factors, principal component analysis, step regression analysis, and sensitivity analysis were conducted. The results show that the runoff capacity of Haihe river basin was mainly controlled by vegetation types and soil texture; catchments with lower runoff capacity were mainly distributed in the upstream/northwest regions. In the catchments with middle runoff capacity, a 10% increase in precipitation (PRE), potential evapotranspiration (PE), and plant-available water coefficient (PAWC) would result in a 23.6% increase, 12.9% decrease, and 5.1% decrease in annual runoff, respectively, whereas in low runoff capacity catchments, a 10% increase in slope and leaf area index (LAI) would result in a 17.8% increase and 10.5% decrease in annual runoff, and in high runoff capacity catchments, a 10% increase in normalized differential vegetation index (NDVI) would result in a 12.6% increase in annual runoff. Soil conditions and vegetation configuration improvement in the upstream of Haihe river basin may contribute to the improvement of available water resources.
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Bhaskar, B. P., Jadish Prasad, and Gopal Tiwari. "Evaluation of agricultural land resources for irrigation in the cotton growing Yavatmal district, Maharashtra, India." Journal of Applied and Natural Science 9, no. 1 (March 1, 2017): 102–13. http://dx.doi.org/10.31018/jans.v9i1.1157.
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The main objective of this study is to evaluate suitability of shrink-swell soils for surface irrigation system based upon a parametric evaluation system in low irrigation potential (7%) of cotton growing Yavatmal district, Maharashtra, India. The thirty three shrink-swell soil series on basaltic landforms were identified from reconnaissance soil survey on 1:50,000 scale and evaluated for surface irrigation methods using Geographic Information System (GIS). The standard weekwise rainfall data showed that the rainfall is less than 20% of total precipitation during September and December, the top A horizon reaches to wilting point and needs supplementary protective irrigation to cotton based cropping systems . It was estimated that ten soil mapping units (1.8 Mha and 13.89%) of shrink-swell soils on moderate slopes (5 to 8%) were evaluated as suitable for surface methods and calculated the irrigation intervals that vary from 8.61±1.35 days for cotton to 8.9±1.4 days for wheat and 10±1.64 days for sugar cane. The study emphasized the utility of soil resource maps helps to delineate the soils with large PAWC(>200mm) with slight yield advantage and will serve as benchmark sites to monitor the interrelationships of soil water dynamics with respect to climate and cotton yields.
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Partridge, Richard. "From paw paws to pentonville." Journal of the Forensic Science Society 26, no. 3 (May 1986): 230. http://dx.doi.org/10.1016/s0015-7368(86)72486-9.
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Hochman, Zvi, Yash P. Dang, Graeme D. Schwenke, Neal P. Dalgliesh, Richard Routley, Michael McDonald, Ian G. Daniells, William Manning, and Perry L. Poulton. "Simulating the effects of saline and sodic subsoils on wheat crops growing on Vertosols." Australian Journal of Agricultural Research 58, no. 8 (2007): 802. http://dx.doi.org/10.1071/ar06365.
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Soils with high levels of chloride and/or sodium in their subsurface layers are often referred to as having subsoil constraints (SSCs). There is growing evidence that SSCs affect wheat yields by increasing the lower limit of a crop’s available soil water (CLL) and thus reducing the soil’s plant-available water capacity (PAWC). This proposal was tested by simulation of 33 farmers’ paddocks in south-western Queensland and north-western New South Wales. The simulated results accounted for 79% of observed variation in grain yield, with a root mean squared deviation (RMSD) of 0.50 t/ha. This result was as close as any achieved from sites without SSCs, thus providing strong support for the proposed mechanism that SSCs affect wheat yields by increasing the CLL and thus reducing the soil’s PAWC. In order to reduce the need to measure CLL of every paddock or management zone, two additional approaches to simulating the effects of SSCs were tested. In the first approach the CLL of soils was predicted from the 0.3–0.5 m soil layer, which was taken as the reference CLL of a soil regardless of its level of SSCs, while the CLL values of soil layers below 0.5 m depth were calculated as a function of these soils’ 0.3–0.5 m CLL values as well as of soil depth plus one of the SSC indices EC, Cl, ESP, or Na. The best estimates of subsoil CLL values were obtained when the effects of SSCs were described by an ESP-dependent function. In the second approach, depth-dependent CLL values were also derived from the CLL values of the 0.3–0.5 m soil layer. However, instead of using SSC indices to further modify CLL, the default values of the water-extraction coefficient (kl) of each depth layer were modified as a function of the SSC indices. The strength of this approach was evaluated on the basis of correlation of observed and simulated grain yields. In this approach the best estimates were obtained when the default kl values were multiplied by a Cl-determined function. The kl approach was also evaluated with respect to simulated soil moisture at anthesis and at grain maturity. Results using this approach were highly correlated with soil moisture results obtained from simulations based on the measured CLL values. This research provides strong evidence that the effects of SSCs on wheat yields are accounted for by the effects of these constraints on wheat CLL values. The study also produced two satisfactory methods for simulating the effects of SSCs on CLL and on grain yield. While Cl and ESP proved to be effective indices of SSCs, EC was not effective due to the confounding effect of the presence of gypsum in some of these soils. This study provides the tools necessary for investigating the effects of SSCs on wheat crop yields and natural resource management (NRM) issues such as runoff, recharge, and nutrient loss through simulation studies. It also facilitates investigation of suggested agronomic adaptations to SSCs.
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Burger, A. F., A. van der Gryp, G. D. van Zyl, and H. G. Fourie. "Simplification of HDM-4 Economic Models for Network-Level Gravel Road Management Systems." Transportation Research Record: Journal of the Transportation Research Board 1819, no. 1 (January 2003): 318–28. http://dx.doi.org/10.3141/1819a-46.
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A description is provided of the procedure followed in the gravel road management system (GRMS) of the Provincial Administration: Western Cape (PAWC) for determining scheduled maintenance priorities and upgrade to paved standard priorities for gravel roads. An algorithm was developed that takes account of a number of factors to determine the costs and benefits of PAWC’s two maintenance strategies. Cost and benefit streams are further used in the calculation of the internal rate of return (IRR) for the different maintenance strategies. Prioritization in the GRMS is based on the calculated IRR, and the priority lists are further refined through a consultative process involving maintenance personnel, the community, and head-office decision makers. As part of the implementation of the algorithm, Highway Development and Management System version 4 (HDM-4) equations for the calculation of vehicle-operating cost (VOC) were simplified for application in the southern African context. Results are presented of a comparison between the output of the simplified HDM-4 equations with the output of HDM-4. Conclusions reached show that implementing the procedure described had a number of positive consequences. They include that the prioritization of projects is based on sound principles that result in the effective and responsible use of available funds. It was also concluded that the simplified HDM-4 VOC calculation results compare well with HDM-4 results.
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Tegner, Christian, Brian Robins, and Henning S. Sørensen. "Crystallization from stratified magmas in the Honningsvåg Intrusive Suite, northern norway: a reappraisal." Mineralogical Magazine 60, no. 398 (February 1996): 41–51. http://dx.doi.org/10.1180/minmag.1996.060.398.04.
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AbstractWedge-shaped layers of ultramafic and mafic cumulates in Intrusion II of the Caledonian Honningsvåg Intrusive Suite suggest crystallization on an inclined magma chamber floor from a compositionally-zoned and density-stratified magma.Cyclic unit 8 (140–100 m thick) consists of a distally-thinning olivine gabbro (denoted paoC) macrolayer overlain by a distally-thickening gabbronorite, pahC. New mineral data in four traverses across cyclic unit 8 show systematic compositional changes; the Mg# of the mafic phases decreases upwards through the unit and distally, both along the base and along the paoC/pahC interface.A crystallization model based on an effectively continuously-zoned magma chamber with numerous, relatively thin, double-diffusive magma layers is proposed. Differential migration of horizontal isopleths (e.g. Mg# and aSiO2) in response to fractional crystallization and assimilation of country rock can explain the variations in the Mg# of the cumulates.
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Mandici, Alexandru, Daniel Eusebiu Cretu, Radu Burlica, Dragos Astanei, Oana Beniuga, Craita Rosu, Denis Constantin Topa, Tudor George Aostacioaiei, Ana Clara Aprotosoaie, and Anca Miron. "Preliminary Study on the Impact of Non-Thermal Plasma Activated Water on the Quality of Triticum aestivum L. cv. Glosa Sprouts." Horticulturae 8, no. 12 (December 7, 2022): 1158. http://dx.doi.org/10.3390/horticulturae8121158.
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The present study aimed to investigate the effects of non-thermal plasma-activated water (PAW) on Triticum aestivum L. cv. Glosa sprouts. Two types of PAW were generated by exposing distilled water to a high-voltage electric discharge. Wheat caryopses were treated either with PAW1 (25 mg/L NO3−, 4 mg/L NO2−, and 6 mg/L H2O2) or PAW2 (35 mg/L NO3−, 5 mg/L NO2−, and 7.5 mg/L H2O2) for 8 days, with samples being collected at days 1, 2, 3, and 8. The germination rate, growth parameters, protein, photosynthetic pigments, total phenolic contents, antioxidant activity of free and bound phenolic fractions, and activity of antioxidant enzymes were evaluated. Both PAW1 and PAW2 had positive effects on Triticum aestivum L. cv. Glosa sprouts. PAW2 had a better impact on sprouts with respect to growth parameters, free phenolic content, and antioxidant activity of the free phenolic fraction (day 3), the accumulation of proteins, and photosynthetic pigments (day 8). In conclusion, exposure to PAW increases the quality of Triticum aestivum L. cv. Glosa sprouts. Further optimization of PAW treatment is required for the most favorable impact on the accumulation of biomass and health-promoting compounds in sprouts.
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Mahé, Gilles. "Observations de Bombus gerstaeckeri Morawitz (Hymenoptera, Apidae) butinant Dephinium dubium (Rouy et Fouc.) Pawl. (Ranunculaceae) dans le Massif des Ecrins (Hautes-Alpes, France)." Osmia 1 (January 2007): 16–19. http://dx.doi.org/10.47446/osmia1.5.
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Observations of Bombus gerstaeckeri Morawitz (Hymenoptera, Apidae) foraging Dephinium dubium (Rouy and Fouc.) Pawl. (Ranunculaceae) in the Massif des Écrins (Hautes-Alpes, France). Bombus gerstaeckeri Morawitz, well-known as a bumblebee specialized on monkshood (Aconitum, Ranunculaceae), was observed in August 2006 in various localities of the Parc Naturel National des Ecrins (Hautes- Alpes, France). In one of the stations, the author noted regular visits of this bumblebee on Delphinium dubium (Rouy et Fouc.) Pawl. (Ranunculaceae), which has never been reported before.
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Ka, Dong Hyeun, Ryza Aditya Priatama, Joo Young Park, Soon Ju Park, Seong Bong Kim, In Ah Lee, and Young Koung Lee. "Plasma-Activated Water Modulates Root Hair Cell Density via Root Developmental Genes in Arabidopsis thaliana L." Applied Sciences 11, no. 5 (March 3, 2021): 2240. http://dx.doi.org/10.3390/app11052240.
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Low-temperature atmospheric pressure plasma technology has been used in agriculture and plant science by direct and indirect treatment of bio-samples. However, the cellular and molecular mechanisms affected by plasma-activated water (PAW) are largely unexplored. In this study, PAW generated from a surface dielectric barrier discharge (SDBD) device was used for plant development. Physicochemical analysis was performed to confirm the PAW properties that correlated with the plasma treatment time. Arabidopsis thaliana L. was utilized to study the effect of the PAW treatment in the early developmental stage. The plasma-activated water samples are denoted as PAW5 time in minutes (min), PAW7 min, PAW12 min, PAW19 min and PAW40 min with the plasma treatment time. Seedlings grown in the PAW5, PAW7 and PAW12 had increased root lengths while the root lengths were decreased in the PAW19 and PAW40. In the cellular level observation, the PAW treatment specifically increased the root hair numbers per unit of the root but suppressed the root hair length in the PAW, indicating that PAW mainly modulates the root hair cell density in the root. Furthermore, we found that the root hair density and length at PAW5 in maximal observed conditions were positively regulated by root developmental-related genes including COBRA-LIKE9 (COBL9), XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE9 (XTH9), XTH17, AUXIN1 (AUX1) and LIKE-AUXIN (LAX3).
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Safrizal, Safrizal. "PRAKTEK GALA UMONG (GADAI SAWAH) DALAM PERSPEKTIF SYARI’AH (STUDI KASUS DI DESA GAMPONG DAYAH SYARIF KECAMATAN MUTIARA KABUPATEN PIDIE PROVINSI ACEH)." Jurnal Ilmiah Islam Futura 15, no. 2 (February 1, 2016): 231. http://dx.doi.org/10.22373/jiif.v15i2.544.
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Gala umong (pawn) has been practiced among Acehnese society until nowadays, whether in urban ur rural areas. This research is aimed at seeing whether the practice of gala umong among acehnese society fulfills the requirements of Islamic shari’a. The result of the study shows that the practice of rice field pawn seing through the Islamic pillars and requirementson pawn has not met the terms of the pillars and rahn or Pawn. The unfulfill practice of pawn can be seen that the unclear statement of the returning deadline that must be conduted by the user. It creates the misunderstandings amongst the parties which finally bring about the hostility among societal members. Another thing which is not in accordance with the rules is that the contract of rahn utilization of Marhuun (collateral), in this case is a productive rice land which is used by the murtahin (pawn recipient). If it is neglected, then the ricest men will use their wealth only for the sake of getting guarantee pawm from the poor for the ongoing investment. As a result, the poor will be more poor as they could not utilize their productive wealth and the ricest will be more rice as plentiful harvest marhūn utilize. Thus, the practice of Gala Umongwhich is practiced at Dayah Sharif village, Pidie sub-district, Aceh province, is not in accordance with Shariah.
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Niu, Xiaoli, Puyu Feng, De-Li Liu, Bin Wang, Cathy Waters, Na Zhao, and Tiancheng Ma. "Deficit Irrigation at Pre-Anthesis Can Balance Wheat Yield and Water Use Efficiency under Future Climate Change in North China Plain." Biology 11, no. 5 (April 30, 2022): 692. http://dx.doi.org/10.3390/biology11050692.
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Background. Deficit irrigation (DI) is a feasible strategy to enhance crop WUE and also has significant compensation effects on yield. Previous studies have found that DI has great potential to maintain crop production as full irrigation (FI) does. Therefore, adopting DI to improve crop production and safeguard groundwater resources is of great importance in water scarce regions, e.g., the North China Plain (NCP). Under the background of global warming, it is worth investigating whether DI continues to play such a key role under future climate scenarios. Methods. We studied the response of winter wheat yield and WUE to different DI levels at pre-anthesis under two Shared Socioeconomic Pathways (SSPs) scenarios (SSP245 and SSP585) using the Agricultural Production Systems Simulator (APSIM) model driven by 21 general circulation models (GCMs) from the Coupled Model Inter-Comparison Project phase 6 (CMIP6). Additionally, we explored the effects of different nitrogen (N) fertilizer application rates on DI. Results. We found that simulated wheat yield would increase by 3.5–45.0%, with WUE increasing by 8.8–46.4% across all treatments under future climate change. Moderate deficit irrigation (DI3, ≤0.4 PAWC at the sowing to flowering stage) under the N3 (150 kg N ha−1) condition was identified as the optimum irrigation schedule for the study site under future climate change. However, compensation effects of DI3 on yield and WUE became weak in the future, which was mainly due to increased growing season rainfall projected by GCMs. In addition, we found that N fertilizer application could mitigate the effect of DI3. Conclusions. We highlight that in water scarce regions of NCP, DI remains an effective strategy to maintain higher yield and enhance water use under future climate scenarios. Results strongly suggest that moderate deficit irrigation under a 150 kg N ha−1 condition could mitigate the contradiction between production and water consumption and ensure food safety in the NCP.
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Whish, Jeremy, Giles Butler, Michael Castor, Shayne Cawthray, Ian Broad, Peter Carberry, Graeme Hammer, Greg McLean, Richard Routley, and Steven Yeates. "Modelling the effects of row configuration on sorghum yield reliability in north-eastern Australia." Australian Journal of Agricultural Research 56, no. 1 (2005): 11. http://dx.doi.org/10.1071/ar04128.
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In recent years, many sorghum producers in the more marginal (<600 mm annual rainfall) cropping areas of Queensland and northern New South Wales have used skip row configurations in an attempt to improve yield reliability and reduce sorghum production risk. This paper describes modifications made to the APSIM sorghum module to account for the difference in water usage and light interception between alternative crop planting configurations, and then demonstrates how this new model can be used to quantify the long-term benefits of skip sorghum production. Detailed measurements of light interception and water extraction from sorghum crops grown in solid, single and double skip row configurations were collected from on-farm experiments in southern Qld and northern NSW. These measurements underpinned changes to the APSIM-Sorghum model so that it accounted for the elliptical water uptake pattern below the crop row and the reduced total light interception associated with skip row configurations. Long-term simulation runs using long-term weather files for locations near the experimental sites were used to determine the value of skip row sorghum production as a means of maintaining yield reliability. These simulations showed a trade-off between long-term average production (profitability) and annual yield reliability (risk of failure this year). Over the long term, the production of sorghum in a solid configuration produced a higher average yield compared with sorghum produced in a skip configuration. This difference in average yield is a result of the solid configuration having a higher yield potential compared with the skip configurations. Skip configurations limit the yield potential as a safeguard against crop failure. To achieve the higher average yield in the solid configuration the producer suffers some total failures. Skip configurations reduce the chance of total failure by capping the yield potential, which in turn reduces the long-term average yield. The decision on what row configuration to use should be made tactically and requires consideration of the starting soil water, the soil’s plant-available water capacity (PAWC), and the farm family’s current attitude to risk.
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Popolizio, Stefano, Anna Maria Stellacci, Luisa Giglio, Emanuele Barca, Matteo Spagnuolo, and Mirko Castellini. "Seasonal and Soil Use Dependent Variability of Physical and Hydraulic Properties: An Assessment under Minimum Tillage and No-Tillage in a Long-Term Experiment in Southern Italy." Agronomy 12, no. 12 (December 10, 2022): 3142. http://dx.doi.org/10.3390/agronomy12123142.
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Defining the optimal sampling time across the growing season is crucial to standardize sampling protocols for soil physical status monitoring and to achieve comparable results under different experimental conditions and on different sites. In this study, the seasonal variability of soil physical and hydraulic properties under two conservative soil management strategies, minimum tillage and no-tillage, was evaluated in a long-term field experiment. On two sampling dates, autumn 2021 and summer 2022, soil bulk density (BD) and volumetric soil water content at the time of the experiments (θi) were measured in each experimental unit and Beerkan infiltration experiments were performed. The soil water retention curve and the hydraulic conductivity function were then estimated using the Beerkan estimation of soil transfer parameters (BEST) methodology. In this way, the saturated hydraulic conductivity (Ks) and a set of capacitive indicators—plant available water capacity (PAWC), soil macroporosity (PMAC), air capacity (AC) and relative field capacity (RFC)—were obtained. Results underlined the role of soil moisture conditions as a main factor affecting variability in soil physical properties. Different soil moisture under autumn and summer samplings significantly affected BD (1.0093 and 1.1905 g cm−3, respectively, in autumn and summer) and Ks (0.0431 and 0.0492 mm s−1). Relationships observed between BEST-derived variables, such as PMAC (or AC) and RFC, and measured variables, such as BD, showed consistent results, with increases in PMAC to BD decreases. However, a comparison of capacity-based indicators obtained by BEST with those obtained from measured soil water retention curves, in a previous year but under comparable soil conditions, highlighted some discrepancies. This finding drives the focus towards the need to use more robust datasets deriving from experimental measurements or from coupling information obtained from measured and estimated data. Finally, this study provided further evidence that, in the long-term field experiment investigated, the two soil management systems allowed keeping the values of key soil physical quality indicators, such as bulk density and saturated hydraulic conductivity, within the optimal or near- optimal reference ranges.
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Nahib, Irmadi, Wiwin Ambarwulan, Ati Rahadiati, Sri Lestari Munajati, Yosef Prihanto, Jaka Suryanta, Turmudi Turmudi, and Anggit Cahyo Nuswantoro. "Assessment of the Impacts of Climate and LULC Changes on the Water Yield in the Citarum River Basin, West Java Province, Indonesia." Sustainability 13, no. 7 (April 1, 2021): 3919. http://dx.doi.org/10.3390/su13073919.
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Changes in climate and land use land cover (LULC) are important factors that affect water yield (WY). This study explores which factors have more significant impact on changes in WY, spatially and temporally, within the Citarum River Basin Unit (RBU), West Java Province, Indonesia with an area of ±11.317 km2. The climate in the area of Citarum RBU belongs to the Am climate type, which is characterized by the presence of one or more dry months. The objectives of the study were: (1) To estimate a water yield model using integrated valuation of ecosystem services and tradeoffs (InVEST), and (2) to test the sensitivity of water yield (WY) to changes in climate variables (rainfall and evapotranspiration) and in LULC. The integration of remote sensing (RS), geographic information system (GIS), and the integrated valuation of ecosystem services and tradeoffs (InVEST) approach were used in this study. InVEST is a suite of models used to map and value the goods and services from nature that sustain and fulfill human life. The parameters used for determining the WY are LULC, precipitation, average annual potential evapotranspiration, soil depth, and plant available water content (PAWC). The results showed that the WY within the territory of Citarum RBU was 12.17 billion m3/year, with mean WY (MWY) of 935.26 mm/year. The results also show that the magnitude of MWY in Citarum RBU is lower than the results obtained in Lake Rawa Pening Catchment Areas, Semarang Regency and Salatiga City, Central Java (1.137 mm/year) and in the Patuha Mountain region, Bandung Regency, West Java (2.163 mm/year), which have the same climatic conditions. The WY volume decreased from 2006, to 2012, and 2018. Based on the results of the simulation, climatic parameters played a major role affecting WY compared to changes in LULC in the Citarum RBU. This model also shows that the effect of changes in rainfall (14.06–27.53%) is more dominant followed by the effect of evapotranspiration (10.97–23.86%) and LULC (10.29–12.96%). The InVEST model is very effective and robust for estimating WY in Citarum RBU, which was indicated by high coefficient of determination (R2) 0.9942 and the RSME value of 0.70.
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Lucena-Agell, Daniel, Antonio Galindo, Herbert N. Arst, and Miguel A. Peñalva. "Aspergillus nidulans Ambient pH Signaling Does Not Require Endocytosis." Eukaryotic Cell 14, no. 6 (April 3, 2015): 545–53. http://dx.doi.org/10.1128/ec.00031-15.
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ABSTRACT Aspergillus nidulans (Pal) ambient pH signaling takes place in cortical structures containing components of the ESCRT pathway, which are hijacked by the alkaline pH-activated, ubiquitin-modified version of the arrestin-like protein PalF and taken to the plasma membrane. There, ESCRTs scaffold the assembly of dedicated Pal proteins acting downstream. The molecular details of this pathway, which results in the two-step proteolytic processing of the transcription factor PacC, have received considerable attention due to the key role that it plays in fungal pathogenicity. While current evidence strongly indicates that the pH signaling role of ESCRT complexes is limited to plasma membrane-associated structures where PacC proteolysis would take place, the localization of the PalB protease, which almost certainly catalyzes the first and only pH-regulated proteolytic step, had not been investigated. In view of ESCRT participation, this formally leaves open the possibility that PalB activation requires endocytic internalization. As endocytosis is essential for hyphal growth, nonlethal endocytic mutations are predicted to cause an incomplete block. We used a SynA internalization assay to measure the extent to which any given mutation prevents endocytosis. We show that none of the tested mutations impairing endocytosis to different degrees, including slaB1 , conditionally causing a complete block, have any effect on the activation of the pathway. We further show that PalB, like PalA and PalC, localizes to cortical structures in an alkaline pH-dependent manner. Therefore, signaling through the Pal pathway does not involve endocytosis.
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Armstrong, RD, NV Halpin, K. McCosker, J. Standley, and AT Lisle. "Applying nitrogen to grain sorghum in central Queensland: residual value and effect of fallowing and tillage practice." Australian Journal of Agricultural Research 47, no. 1 (1996): 81. http://dx.doi.org/10.1071/ar9960081.
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In the northern cereal belt of Australia, farmers are reluctant to apply nitrogen (N) fertilizers because of a perception that if N is added to the soil and no crop is subsequently planted due to lack of rain, the N is 'lost'. An experiment was conducted on a cracking clay soil over three seasons to compare the response of grain sorghum to N applied to the current crop v. N applied the previous season which was then either planted or left fallow (to simulate a missed planting opportunity). Recovery of 15~-labelled fertilizer by the crop and that remaining in the soil were simultaneously determined in microplots. The effect of tillage practice [zero (ZT) and conventional (CT)] was also examined. Sorghum grain yield responded to fresh applications of N in 1993 and 1993194 but not 1992, reflecting the importance of timing of rainfall rather than the total amount received within the season. Applications of N to the current crop always improved yield more than equivalent amounts of N applied to the previous crop. Grain yields of plots that were previously fallowed (fallow-sorghum rotation) were higher than the combined yields of sorghum-sorghum rotations, although fallowing was an inefficient means of accumulating both water and mineral N. Recovery of applied 1 5 ~ by sorghum varied from 48% in 1992 to 36% in 1993 but was not related to the overall N responsiveness of the crop. Sorghum recovered a similar proportion of 1 5 ~ from plots which had been fertilized and then fallowed the previous year compared to fresh applications to the current crop, despite the fallow plots having less 1 5 ~ in them due to losses from the previous season. Losses of 1 5 ~ from the soil/plant system varied markedly with year and appeared to be related to the pattern of rainfall occurring and its possible effect on denitrification. Tillage practice did not affect grain yields or PAWC, had minimal effect on the amount of mineral N present, and little influence on the fertilizer N requirements of sorghum per se. This study suggests that there is only a small residual value to subsequent sorghum crops of fertilizer N if added initially to a successful crop. However, if N is applied pre-plant and the crop is not planted, for example due to lack of planting rain, a large proportion of this N can remain available to the following crop depending on the nature of the subsequent rainfall.
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Alam, Md, Richard Bell, Nazmus Salahin, Shahab Pathan, A. T. M. A. I. Mondol, M. J. Alam, M. H. Rashid, P. L. C. Paul, M. I. Hossain, and N. C. Shil. "Banding of Fertilizer Improves Phosphorus Acquisition and Yield of Zero Tillage Maize by Concentrating Phosphorus in Surface Soil." Sustainability 10, no. 9 (September 10, 2018): 3234. http://dx.doi.org/10.3390/su10093234.
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Zero tillage increases stratification of immobile nutrients such as P. However, it is unclear whether near-surface stratification of soil P eases or hampers P uptake by maize (Zea mays L.) which needs an optimum P supply at/before six–leaf–stage to achieve potential grain yield. The aim of the three-year study was to determine whether P stratification, under zero tillage, impaired yield of maize and which P placement methods could improve P uptake on an Aeric Albaquept soil subgroup. Phosphorus fertilizer was placed by: (a) broadcasting before final tillage and sowing of seeds; (b) surface banding beside the row; and (c) deep banding beside the row (both the band placements were done at three–four leaf stage) Phosphorus treatments were repeated for 3 years along with three tillage practices viz.: (a) zero tillage (ZT); (b) conventional tillage (12 cm; CT); and (c) deep tillage (25 cm; DT). In the third year, all the tillage practices gave similar yield of Bangladesh Agricultural Research Institute (BARI) hybrid maize–5, but the highest grain yield was obtained by surface band P placement. After three years of tillage and P placements, the root mass density (RMD) at 0–6 cm depth increased significantly from 1.40 mg cm−3 in DT under deep band placement to 1.98 mg cm−3 in ZT under surface band placement, but not at the other depths. The combination of ZT practices, with broadcast or surface band placement methods, produced the highest available, and total P, content in soil at 0–6 cm depth after harvesting of maize. Accordingly, a significant increase in P uptake by maize was also found with surface banding of P alone and also in combination with ZT. Organic carbon, and total N, also increased significantly at depths of 0–6 cm after three years in ZT treatments with P placed in bands. By contrast, CT and DT practices, under all placement methods, resulted in an even distribution of P up to 24 cm depth. Phosphorus application, by surface banding at the three–four leaf stage, led to increased P uptake at early growth and silking stages, which resulted in highest yield regardless of tillage type through increased extractable P in the soil. Even though ZT increased P stratification near the soil surface, and it increased plant available water content (PAWC) and RMD in the 0–6 cm depth, as did surface banding, it did not improve maize grain yield. Further research is needed to understanding the contrasting maize grain yield responses to P stratification.
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Kubone, Purity Z., Koleka P. Mlisana, Usha Govinden, Akebe Luther King Abia, and Sabiha Y. Essack. "Antibiotic Susceptibility and Molecular Characterization of Uropathogenic Escherichia coli Associated with Community-Acquired Urinary Tract Infections in Urban and Rural Settings in South Africa." Tropical Medicine and Infectious Disease 5, no. 4 (November 27, 2020): 176. http://dx.doi.org/10.3390/tropicalmed5040176.
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We investigated the phenotypic and genotypic antibiotic resistance, and clonality of uropathogenic Escherichia coli (UPEC) implicated in community-acquired urinary tract infections (CA-UTIs) in KwaZulu-Natal, South Africa. Mid-stream urine samples (n = 143) were cultured on selective media. Isolates were identified using the API 20E kit and their susceptibility to 17 antibiotics tested using the disk diffusion method. Extended-spectrum β-lactamases (ESBLs) were detected using ROSCO kits. Polymerase chain reaction (PCR) was used to detect uropathogenic E. coli (targeting the papC gene), and β-lactam (blaTEM/blaSHV-like and blaCTX-M) and fluoroquinolone (qnrA, qnrB, qnrS, gyrA, parC, aac(6’)-Ib-cr, and qepA) resistance genes. Clonality was ascertained using ERIC-PCR. The prevalence of UTIs of Gram-negative etiology among adults 18–60 years of age in the uMgungundlovu District was 19.6%. Twenty-six E. coli isolates were obtained from 28 positive UTI samples. All E. coli isolates were papC-positive. The highest resistance was to ampicillin (76.9%) and the lowest (7.7%) to amoxicillin/clavulanic acid and gentamycin. Four isolates were multidrug-resistant and three were ESBL-positive, all being CTX-M-positive but SHV-negative. The aac(6’)-Ib-cr and gyrA were the most detected fluoroquinolone resistance genes (75%). Isolates were clonally distinct, suggesting the spread of genetically diverse UPEC clones within the three communities. This study highlights the spread of genetically diverse antibiotic-resistant CA-UTI aetiologic agents, including multidrug-resistant ones, and suggests a revision of current treatment options for CA-UTIs in rural and urban settings.
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Jo, Hyunji, Seri Park, Hye Ryeon Kim, Hongsik Kim, Joohyun Hong, Jeong Eon Lee, Jonghan Yu, et al. "Long-Term Breast Cancer Outcomes of Pregnancy-Associated Breast Cancer (PABC) in a Prospective Cohort." Cancers 14, no. 19 (October 4, 2022): 4839. http://dx.doi.org/10.3390/cancers14194839.
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Background: Given that peak age of breast cancer (BC) is younger in Asians than in Western populations, relatively higher prevalence of pregnancy-associated breast cancer (PABC) has been reported. This study aimed to analyze the characteristics and clinical outcomes of PABC in Korea. Methods: We defined PABC as BC diagnosed during pregnancy or in the first postpartum year. We compared the clinicopathological characteristics and BC outcomes between patients with PABC and non-PABC patients in the prospective YBC cohort from Samsung Medical Center. Results: In total, 1492 patients were initially enrolled, and 1364 patients were included, of which 93 had PABC (6.8%). The median age of patients with PABC was 34 years. Hormone receptor expression was lower (64.6% vs 74.6%) and frequency of HER2 overexpression was higher (26.9% vs 17.6%) in patients with PABC than in non-PABC patients. The 5-year overall survival (OS) rates were 83.2% and 93.4% in patients with PABC and non-PABC patients, respectively (p < 0.001). The 5-year disease-free survival (DFS) rates were 72.2% and 83.8% in PABC and non-PABC patients. Conclusion: Compared to non-PABC patients, patients with PABC had poorer OS and DFS in this prospective cohort. Exploratory biomarker analysis for PABC is warranted.
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Silva, Edna Oliveira, Anselmo José Perez, Luiz Aparecido Bortolotto, Wellington Lunz, José Geraldo Mill, and Luciana Carletti. "Pressão arterial e indicadores de função vascular de corredores com diferentes níveis de desempenho no teste cardiopulmonar." Revista Brasileira de Educação Física e Esporte 31, no. 4 (December 23, 2017): 747–58. http://dx.doi.org/10.11606/1807-5509201700040747.
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O objetivo deste estudo foi comparar os valores de pressão arterial sistólica e diastólica periférica (PASp e PADp) e central (PASc e PADc) e o índice de função vascular em corredores de rua de diferentes desempenhos. A amostra foi composta por 48 participantes, 20-40 anos, 32 corredores de rua com diferentes níveis de desempenho, e 16 indivíduos sedentários. Avaliou-se a aptidão cardiorrespiratória e a velocidade máxima de corrida, através do teste cardiopulmonar de exercício (TCPE). A pressão central e periférica foi investigada por tonometria de aplanação e a velocidade da onda de pulso (VOP) pelo equipamento Complior. O ecocardiograma foi usado para avaliar a estrutura cardíaca. ANOVA de uma via foi utilizada considerando p <0,05. A ANCOVA foi usada para ajustar fatores de confusão. Corredores com desempenho superior apresentaram menor PASp que os demais grupos (120±7 vs 127±8 vs 130 ±8 mmHg). A duração da diástole foi maior nos corredores com desempenho superior (845±92 ms) em relação aos corredores com desempenho inferior (786±174 ms e controle (641±128 ms). O índice de amplificação (AI) não foi diferente entre os grupos (109 ± 21%; 109 ± 11%; 110 ± 1%) assim como a VOP (7,1 ± 1ms. 7,6 ± 1.1ms. 8,0 ± 1,1ms). Corredores com desempenho superior apresentaram maior massa do ventrículo esquerdo (MVE g/m²) em relação aos demais (116±12 g/m² vs 100±18 g/m² vs 86±13 g/m²), e menor débito cardíaco em comparação ao grupo controle (4,8±1 l/ min. vs 6,0±1 l/min). Portanto corredores com desempenho superior apresentaram maior MVE g/m², menor débito cardíaco, menor PASc e PASp, e melhor duração da diástole que seus pares sedentários, mas não apresentam melhores indicadores de função vascular na mesma comparação.
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Ma, Song Jiang, Mei Ling Fu, Fang Wen Li, Nian Fen Wu, Juan Yang, Hai Wu Jia, Bing Wang, and Rui Cheng. "Preparation of a New Inorganic-Organic Composite Dual-Coagulant and Application of Oily Wastewater Treatment." Advanced Materials Research 233-235 (May 2011): 523–27. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.523.
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A new inorganic-organic composite dual-coagulant (PAFC-CPAM) was prepared by polyaluminum ferric chloride (PAFC) and cationic polyacrylamide (CPAM) and its treatment efficiency for oily wastewater was evaluated by coagulation jar tests. PAFC-CPAM dual-coagulants were characterized by FT-infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The FTIR spectra illustrated that there were some chemical reactions between PAFC and CPAM in PAFC-CPAM. SEM micrographs testified that PAFC-CPAM formed compact net structure which is different from PAFC and CPAM, resulting to its outstanding coagulation performance other than monomeric coagulant in treating oily wastewater. Coagulation jar tests presented that PAFC-CPAM improved 1.14% and 0.38% of oil removal rate and reduced 0.35NTU and 0.06NTU of residual turbidity than PAFC and CPAM respectively at the optimal dosage of 120mg/L. PAFC-CPAM enhanced 4.56% and 2.12% of oil removal efficiency and decreased 0.27NTU and 0.01NTU of residual turbidity on average in comparison with PAFC and CPAM respectively in the pH range of 4.0-8.0. All of above-mentioned experiment results demonstrated that PAFC-CPAM behaved superior coagulation performance than PAFC and CPAM.
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Skaar, Jeffrey R., Takehiro Arai, and James A. DeCaprio. "Dimerization of CUL7 and PARC Is Not Required for All CUL7 Functions and Mouse Development." Molecular and Cellular Biology 25, no. 13 (July 1, 2005): 5579–89. http://dx.doi.org/10.1128/mcb.25.13.5579-5589.2005.
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ABSTRACT CUL7, a recently identified member of the cullin family of E3 ubiquitin ligases, forms a unique SCF-like complex and is required for mouse embryonic development. To further investigate CUL7 function, we sought to identify CUL7 binding proteins. The p53-associated, parkin-like cytoplasmic protein (PARC), a homolog of CUL7, was identified as a CUL7-interacting protein by mass spectrometry. The heterodimerization of PARC and CUL7, as well as homodimerization of PARC and CUL7, was confirmed in vivo. To determine the biological role of PARC by itself and in conjunction with CUL7, a targeted deletion of Parc was created in the mouse. In contrast to the neonatal lethality of the Cul7 knockout mice, Parc knockout mice were born at the expected Mendelian ratios and exhibited no apparent phenotype. Additionally, Parc deletion did not appear to affect the stability or function of p53. These results suggest that PARC and CUL7 form an endogenous complex and that PARC and CUL7 functions are at least partially nonoverlapping. In addition, although PARC and p53 form a complex, the absence of effect of Parc deletion on p53 stability, localization, and function suggests that p53 binding to PARC may serve to control PARC function.
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Noh, Hyun-Ju, Seung Chul Shin, Yerin Park, Ahyoung Choi, Kiwoon Baek, Soon Gyu Hong, Yong-Joon Cho, Hyoungseok Lee, and Yung Mi Lee. "Lichenicola cladoniae gen. nov., sp. nov., a member of the family Acetobacteraceae isolated from an Antarctic lichen." International Journal of Systematic and Evolutionary Microbiology 70, no. 11 (November 1, 2020): 5918–25. http://dx.doi.org/10.1099/ijsem.0.004495.
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Two Gram-stain-negative, facultative anaerobic, chemoheterotrophic, pink-coloured, rod-shaped and non-motile bacterial strains, PAMC 26568 and PAMC 26569T, were isolated from an Antarctic lichen. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains PAMC 26568 and PAMC 26569T belong to the family Acetobacteraceae and the most closely related species are Gluconacetobacter takamatsuzukensis (96.1 %), Gluconacetobacter tumulisoli (95.9 %) and Gluconacetobacter sacchari (95.7 %). Phylogenomic and genomic relatedness analyses showed that strains PAMC 26568 and PAMC 26569T are clearly distinguished from other genera in the family Acetobacteraceae by average nucleotide identity values (<72.8 %) and the genome-to-genome distance values (<22.5 %). Genomic analysis revealed that strains PAMC 26568 and PAMC 26569T do not contain genes involved in atmospheric nitrogen fixation and utilization of sole carbon compounds such as methane and methanol. Instead, strains PAMC 26568 and PAMC 26569T possess genes to utilize nitrate and nitrite and certain monosaccharides and disaccharides. The major fatty acids (>10 %) are summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c; 40.3–40.4 %), C18 : 1 2OH (22.7–23.7 %) and summed feature 2 (C14 : 0 3OH and/or C16 : 1 iso I; 12.0 % in PAMC 26568). The major respiratory quinone is Q-10. The genomic DNA G+C content of PAMC 26568 and PAMC 26569T is 64.6 %. Their distinct phylogenetic position and some physiological characteristics distinguish strains PAMC 26568 and PAMC 26569T from other genera in the family Acetobacteraceae supporting the proposal of Lichenicola gen. nov., with the type species Lichenicola cladoniae sp. nov. (type strain, PAMC 26569T=KCCM 43315T=JCM 33604T).