Effect of soil salinity on internal browning of potato tuber tissue in two soil types

A study was carried out with potato (Solanum tuberosum; cv. Atlantic) during 2001 and 2002 to determine the effect of soil salinity on internal tuber browning. The effect of varying levels of soil salinity on proline content, polyphenol oxidase enzyme activity, and chlorogenic acid content in potato leaves and tubers was examined. NaCl treatments (2.1, 4.25, 6.38, 8.5 g NaCl L^?1) were applied to the pots, the first 46 days after planting, and four additional treatments were applied, each about 7 days apart. Increasing NaCl concentrations resulted in an increase in browning of tuber tissue and proline content in the tubers. Chlorogenic acid content in the leaves increased up to 6.4 g NaCl L^?1, but then decreased at 8.5 g NaCl L^?1 and in tubers tended to be maximal at the highest saline concentration tested (8.5 g NaCl L^?1). Increasing NaCl concentration resulted in a reduction in yield per plant and average tuber weight, and also increased tuber number. There were major differences in the impact of salinity over the 2-year period, which was probably due to the impact of the growing media; a low organic matter (about 1% OM) silty loam soil and a high organic content (about 90% OM) Muck soil were used in 2001 and 2002, respectively. Tuber browning increased linearly with salinity in 2002, but only markedly increased at 8.5 g NaCl L^?1 in 2001. Sodium and chloride ion concentration was always greater (about two times) at equivalent application rates in the 2002 trial. The high organic matter content soil retained sodium and chloride ions more effectively than the silty loam soil and enhanced the impact of increased salinity concentration on physiological properties of potato plants and particularly on tuber tissue browning and proline accumulation.     

Impacts of perforated sheet pipe installation on some paddy soil properties

Paddy and Water Environment - Today, the world’s vision emphasizes the development of climate-adaptive agriculture for food security and provision of water with safe technology. Under extreme...     

The influence of some soil physical properties on potato yields and grade distribution

Yields of U. S. No. 1 potatoes and numbers of deformed tubers were significantly correlated with air permeability near the surface and soil bulk densities down to 8 inches. Yields of No. 1 grade were correlated positively with soil air permeability and negatively with soil bulk density, whereas for deformed tuber production the correlations were the reverse. Total tuber production had a low correlation with soil factors because of the opposing responses of U. S. No. 1’s and deformed tubers. In a multiple-regression analysis, large variations in total yield, grade distribution, emergence rate, and final stand were accounted for by considering soil bulk density, soil strength, and air permeability. Production of quality tubers was closely associated with mechanical-impedance factors in the immediate zone of tuber development. Yields of U. S. No. 1’s were reduced 35% by a severe soil-compaction treatment in the beds.     

不同大豆品种在酸性红壤和石灰性土壤上耐低磷能力的差异

研究不同耐低磷大豆品种在酸性红壤和石灰性土壤上的耐性变化。结果表明,大豆品种的耐低磷能力与土壤类型有一定关系,干物质积累量和磷积累量的大豆品种×土壤类型间交互作用极显著。在酸性低磷红壤上,大豆品种湘春９１—１００、涟源泥冬黄豆和浙春２ 号的干物质量和磷积累量都显著高于桂阳傲泉黄豆和湘豆３ 号。在石灰性土壤上,干物质表现为湘春９１—１００、涟源泥冬黄豆＞ 桂阳傲泉黄豆、浙春２ 号＞ 湘豆３ 号,而磷积累量除湘春９１—１００ 显著较高外,其它４ 个品种间无显著差异。土壤类型对大豆品种的根系生长有较大影响     

多环芳烃对土壤线虫和微生物生物量的影响

通过向土壤中添加不同浓度的3种多环芳烃（PAHs）蒽、2-甲基蒽和7,12-二甲基苯并[a]蒽,研究PAHs对土壤微生物生物量碳和土壤线虫的影响。结果表明,土壤微生物生物量碳随PAHs浓度增加而呈指数下降,说明PAHs可抑制土壤微生物活性。土壤线虫总数随PAHs浓度不同而变化,低浓度和高浓度条件下土壤线虫总数增加,中等浓度对土壤线虫总数无影响。土壤线虫中食植物线虫和食细菌线虫占总数的81.8%,PAHs加入后此两类线虫仍占绝对优势,占总数的77.0%-92.8%。但线虫营养类群发生变化,食植物线虫和杂食性线虫比例增高,而食细菌线虫和食真菌线虫比例趋于降低,这主要由PAHs对土壤微生物的影响所致。     

Evaluation of spatial variability of the integral energy of plant available water and its influential properties in paddy soil

Paddy and Water Environment - Plant Available Water is the main concept for describing the existing water content in a soil profile. Along with this concept, Integral Energy shows the energy...     

Variance of microbial composition and structure and relation with soil properties in rhizospheric and non-rhizospheric soil of a flooded paddy

Paddy and Water Environment - Soil microbial structure and nutrient properties varied with fertilization and plant growth simultaneously in the rhizosphere. However, the relationships between...     

Effect of water management on greenhouse gas emissions and microbial properties of paddy soils in Japan and Indonesia

This research aims at elucidating the greenhouse gas emissions and its related soil microbial properties in continuously flooded or intermittently drained paddy soils in Japan and Indonesia. The study in Japan comprises alluvial soil and peat, cultivated to rice variety Nipponbare, while in Indonesia comprised alluvial soil cultivated to rice variety Siam Pandak. Intermittent drainage was performed to half number of the plot in 6 days interval, starting at tillering or heading stage of rice, while the other half number of plot was kept flooded as control. The experiments were carried out to follow the randomized block design with three replications. Gas samples were taken in weekly basis, except during the treatments (i.e., every 2 days interval) and analyzed for methane (CH₄) and nitrous oxide (N₂O) concentrations. Soil samples were and analyzed for the population of methanogenic bacteria, denitrifiers, methane production and consumption potentials, and methanogenic substrate. Plant growth parameters were also observed. The results showed that intermittent drainage significantly reduced greenhouse gas emission from paddy soil of Indonesia and Japan without significant changes in soil microbial population. The reductions of greenhouse emission from Japanese peaty and alluvial paddy soil due to intermittent drained were about 32 and 37%, respectively. Meanwhile, the reductions in greenhouse gas emission from alluvial soil of Indonesia due to intermittent drainage were very similar to that of in Japan, i.e., average about 37%. This suggests that intermittent drainage can be an appropriate technology option to reduce the greenhouse gas emission from paddy soil in Japan and Indonesia.     

Improving crop yield and N uptake with long-term straw retention in two contrasting soil types

Retention and/or reincorporation of plant residues increases soil organic nitrogen (N) levels over the long-term is associated with increased crop yields. There is still uncertainty, however, about the interaction between crop residue (straw) retention and N fertilizer rates and sources. The objective of the study was to assess the influence of straw management (straw removed [S_Rem] and straw retained [S_Ret]), N fertilizer rate (0, 25, 50 and 75 kg N ha⁻¹) and N source (urea and polymer-coated urea [called ESN]) under conventional tillage on seed yield, straw yield, total N uptake in seed + straw and N balance sheet. Field experiments with barley monoculture (1983-1996), and wheat/barley-canola-triticale-pea rotation (1997-2009) were conducted on two contrasting soil types (Gray Luvisol [Typic Haplocryalf] loam soil at Breton; Black Chernozem [Albic Argicryoll] silty clay loam at Ellerslie) in north-central Alberta, Canada. On the average, S_Ret produced greater seed yield (by 205-220 kg ha⁻¹), straw yield (by 154-160 kg ha⁻¹) and total N uptake in seed + straw (by 5.2 kg N ha⁻¹) than S_Rem in almost all cases in both periods at Ellerslie, and only in the 1997-2009 period at Breton (by 102 kg seed ha⁻¹, 196 kg straw ha⁻¹ and by 3.7 kg N ha⁻¹) for both N sources. There was generally a considerable increase in seed yield, straw yield and total N uptake in seed + straw from applied N up to 75 kg N ha⁻¹ rate for both N sources at both sites and more so at Breton, but the response to applied N decreased with increasing N rate. The ESN was superior to urea in increasing seed yield (by 109 kg ha⁻¹), straw yield (by 80 kg ha⁻¹) and total N uptake in seed + straw (by 2.4 kg N ha⁻¹) in the 1983-1996 period at Breton (mainly at the 25 and 50 kg N ha⁻¹ rates). But, urea produced greater straw yield (by 95 kg ha⁻¹) and total N uptake in seed + straw (by 3.3 kg N ha⁻¹) than ESN in the 1983-1996 period at Ellerslie. The N balance sheets over the 1983-2009 study duration indicated large amounts of applied N unaccounted for (ranged from 740 to 1518 kg N ha⁻¹ at Breton and from 696 to 1334 kg N ha⁻¹ at Ellerslie), suggesting a great potential for N loss from the soil-plant system through denitrification and/or nitrate leaching, and from the soil mineral N pool by N immobilization. In conclusion, the findings suggest that long-term retention of crop residue may gradually improve soil productivity. The effectiveness of N source varied with soil type.     

Preparation and properties of an eco-friendly superabsorbent based on flax yarn waste for sanitary napkin applications

Recently, cellulose-based superabsorbent has attracted attention as a promising material in many fields because of its rich sources and outstanding properties of biodegradability and biocompatibility. This study examines the potential application of a novel flax yarn waste-g-poly(acrylic acid-co-acrylamide) (FYW/PAA) superabsorbent in the absorbent core layer of sanitary napkins. Acrylic acid (AA) and acrylamide (AM) were grafted onto the pretreated flax yarn waste (PFYW) by free-radical graft copolymerization in homogeneous aqueous solution. The synthesis conditions of the FYW/PAA superabsorbent and its application performance for sanitary napkin were investigated. The results showed that, under the optimal synthesis conditions, the water absorbency of the prepared FYW/PAA reached 787.6 g/g in deionized water, 109.5 g/g in 0.9 wt% NaCl solution and 206.5 g/g in artificial blood solution. The composited absorbent core layer containing the FYW/PAA achieved the similar artificial blood solution absorbency of 192.6 g/g and retention of 83.9 wt% to those of the marketed sanitary napkin products. Meanwhile, a weight residue of 53.6 wt% was attained for the FYW/PAA after being buried in soil for 90 d.     

广西主要蔗区宿根蔗根际土壤微生物群落结构分析

探讨了广西主要蔗区宿根蔗根际土壤微生物的分布情况,结果表明：宿根蔗根际土壤微生物数量总体上表现为：细菌〉真菌〉放线菌。但宜州市和北海市土壤中真菌数量〉放线菌;崇左市土壤中真菌和放线菌相当。     

Nitrate leaching from cut grassland as affected by the substitution of slurry with nitrogen mineral fertilizer on two soil types

A field experiment was conducted to find out whether there is any difference in risk of N leaching to groundwater when cattle slurry and/or mineral fertilizer-N was applied to cut grassland. The experiment was carried out over two consecutive years on two sites (one with a relatively wet sandy soil and one with a relatively dry sandy soil). Treatments were mineral fertilizer-N at annual rates of 0–510 kg N ha⁻¹ year⁻¹ and combinations of sod-injected cattle slurry (85, 170, 250 and 335 kg N ha⁻¹ year⁻¹) and mineral fertilizer-N (289, 238, 190 and 139 kg N ha⁻¹ year⁻¹). Yield responses indicated that in the short run, 0·44–0·88 (average 0·60) of the slurry-N was as available as mineral fertilizer-N. The total N input from mineral fertilizer and slurry was a worse predictor of nitrate leaching (     0·11) than the N surplus (i.e. the difference between total N input and harvested N) (     0·60). The effective N surplus, based on the difference between the summed inputs of the plant-available N and harvested N, proved to be the best indicator of leaching (     0·86). Annual N application rates of up to 340 kg plant-available N ha⁻¹ complied with the target nitrate concentration in groundwater of 11·3 mg N L⁻¹ set by the European Union in both years on the wet sandy soil, whereas on the dry sandy soil none of the treatments did.     

Potato responses to calcium application on several soil types

On low cation exchange capacity, sandy soils where soil test Ca is low, potato tuber (Solanum tuberosum L.) Ca levels may not be optimal for maximum yield or quality; therefore, this study evaluated the effect of several levels of applied Ca on potato yield and quality on four soil types in Wisconsin. Calcium was applied to a Plainfield loamy sand, a Keiner loamy sand, a Pence sandy loam, and an Antigo silt loam at five rates in 1984 (0, 84, 252, 420, and 588 kg Ca ha^?1) and at six rates in 1985 (0, 56, 112, 168, 224, and 336 kg Ca ha^?1) as a band of CaSO₄ in the hill. In 1984, on the Plainfield soil, three rates of sidedress Ca(NO₃)₂ (0, 84, and 168 kg Ca ha_?1) were factorially combined with the five CaSO₄ treatments to evaluate the efficacy of Ca(NO₃)₂ as a concomitant Ca and N source. In general, total yield was not affected by CaSO₄ additions; however, the addition of approximately 100 kg Ca ha^?1 as Ca(NO₃)₂ increased total yield 3.6 Mg ha^?1. On the low-CEC, low-Ca soils (Plainfield and Kelner), improved tuber grade and/ or US1A size grade were detected with the addition of up to approximately 300 kg Ca ha^?1 as CaSO₄. The percent of US1A tubers increased 5 to 10% and the yield of US1A prime size (170–370 g) tubers increased 3.4 to 8.4 Mg ha^?1 above control values. These improvements were accompanied by increased periderm Ca concentrations, even though leaflet Ca concentrations were not affected by Ca applications. The use of 100 kg Ca ha^?1 asCa(NO₃)₂ in combination with CaSO₄ was more effective than CaSO₄ alone. On higher soil test Ca soils (Pence and Antigo), responses were inconsistent and periderm Ca was generally not increased.     

Impacts of biocontrol products on Rhizoctonia disease of potato and soil microbial communities,and their persistence in soil

Four commercial biocontrol formulations (Bacillus subtilis GB03, Burkholderia ambifaria type Wisconsin isolate J82, Trichoderma virens Gl-21, and Trichoderma harzianum strain T-22), a chemical seed treatment (thiophanate-methyl, mancozeb, and cymoxanil mixture, TMC), and a combination chemical/biological treatment, were compared with no-pathogen and pathogen-treated controls, and monitored in two field seasons in Maine for their effects on the development of Rhizoctonia disease of potato and soil microbial community characteristics. All treatments reduced the incidence and severity of stem canker (37–75% reduction) relative to the pathogen control over both years, with the best control provided by B. subtilis and the combination chemical/biological treatment (TMC/Bamb). Both bacterial treatments (B. subtilis and Bu. ambifaria) reduced severity of black scurf in both years, and T. virens reduced scurf in one year, with reductions of 11–20% relative to the pathogen control. Over both years, the B. subtilis, T. virens, and TMC/Bamb treatments increased total and marketable yield, and Bu. ambifaria increased marketable yield, by 11–15% relative to the pathogen control. Substantial populations of the added fungal agents, but not the bacteria, were detected in bulk soil at the end of the growing season. Biocontrol treatments also significantly (P < 0.05) affected soil microbial community characteristics, as assessed by single carbon source substrate utilization (SU) and whole soil fatty acid methyl ester (FAME) profiles. Bacterial biocontrol treatments generally resulted in higher microbial activity and substrate utilization. Some effects on soil microbial communities were also observed the following spring (1 yr after application). This research indicates that biocontrol treatments can assist in the control of Rhizoctonia disease of potato, persist in soil to some degree, and have significant effects on soil microbial communities long after application.     

How two ridges and the furrow mulched with plastic film affect soil water,soil temperature and yield of maize on the semiarid Loess Plateau of China

Plastic film mulching is an effective practice to improve water harvest and crop productivity in semiarid areas. The grain yield of maize (Zea mayis) as affected by various mulching practices was studied in the field in 2006 and 2007 to determine a mulching pattern that would increase rainwater harvest and crop yield. In 2006, three treatments were used: (1) flat plot without mulch (CK); (2) two ridges and furrows mulched by one plastic film and maize planted in the furrow between the two ridges (DRM); (3) two rows of maize planted in a ridged bed mulched with plastic (RM). Two additional treatments were tested in 2007: (4) two rows of maize mulched with a 70-cm wide plastic film and then 30 cm of bare soil alternated (NM); (5) maize planted without ridges in double rows 80 cm apart and the whole plot mulched with plastic film (WM). Maize yield was highest in the DRM treatment: 1150 kg ha⁻¹ in 2006 and 6130 kg ha⁻¹ in 2007. This was associated with better topsoil moisture in the planting zone and higher soil temperature in the DRM treatment compared with the other treatments. The soil moisture in DRM reached 10.5% and 22.6%, in 2006 and 2007, respectively, the highest of all the treatments. The mean temperature in DRM was higher than in CK and RM by 1.2 °C and 0.4 °C, respectively in 2006, while in 2007, it was higher than that in CK by 3.1 °C, in RM by 0.6 °C, in NM by1.7 °C and in WM by 0.6 °C in 2007. The higher temperatures in the DRM treatments resulted in the maize maturing earlier than in the other mulched treatments, 15 days earlier than in RM in 2006 and 11 days, 3 days, and 14 days earlier than in RM, WM, and NM, respectively in 2007. The highest water-use efficiency (WUE) was found in DRM in both years. In 2006, the WUE in DRM was six times greater than that in CK and 9.96% greater than in RM. In 2007, the WUE for grain in the DRM treatment was 16.6 kg ha⁻¹ mm⁻¹, 11 times greater than that in CK and greater than RM, NM and WM by 67.7%, 26.7% and 9.2%, respectively. It is concluded that the double ridges and furrow mulching treatment could serve as a model for maize production for small-holder farmers in semiarid regions.     

Effect of calcium silicate on growth and dry matter yield of Chloris gayana and Sorghum sudanense under two soil water regimes

The effects of five rates [0 (control), 1, 2, 4 and 6 Mg ha^?1] of calcium silicate on the growth and water consumption by rhodes grass (Chloris gayana Kunth) and sudan grass (Sorghum sudanense Piper) under wet and dry soil water regimes (60 g and 30 g H₂O kg^?1 soil respectively) were evaluated in a pot experiment. The effect of the application of silicate on plant biomass was similar to that of the control. However, the shoot and root dry mass varied significantly (P < 0.001) according to the soil water regime and plant species. During the first cut, the shoot dry mass was 5.7 g per pot under the wet soil moisture regime, significantly exceeding that under the dry soil water regime proportionately by 0.68. For sudan grass, the shoot dry mass varied from 3.6 g per pot in the control to 4.3 g per pot in the treatment that received 6 Mg ha^?1 of calcium silicate. Plant water demand decreased as the rate of calcium silicate application increased, suggesting that an application of calcium silicate could reduce drought stress and enhance water economy. For the soil under study, the reduction in plant water demand represents a water saving ranging from 0.076 to nearly 0.20.     

Evaluation of treatments with hot water,chemicals and ventilated containers to reduce microbial spoilage in irradiated potatoes

Summary Potatoes irradiated to control sprouting were dipped in: hot water (56°C, 5 min; 52°C, 10, 15 and 20 min); cold (25°C, 5 min) or hot (56°C, 5 min) salicylic acid (1000 and 2000 ppm); or sodium hypochlorite (0.1 and 0.2%, 5 min); or dusted with salicylic acid (1 and 2%), to try to reduce the incidence of bacterial soft rot (Erwinia sp.) during controlled temperature (10°C, 15°C) and ambient temperature (20–34°C) storage. All treatments, particularly hot water and hot salicylic acid dip, increased microbial spoilage, possibly as a result of handling damage during the treatments combined with the inhibition of wound periderm formation as a result of irradiation. Storing irradiated tubers in well ventilated containers reduced soft rot compared to storing them in sacks and after 6 months storage at 10, 15 and 20–34°C, 95, 90 and 77% respectively were healthy and marketable.     

Root growth,soil water content and yield of barley under different tillage systems on two soils in semiarid conditions

An experiment was conducted on two soils in a semiarid area in the Spain’s Ebro valley. Soil A was a Fluventic Xerochrept of 120 cm depth and Soil B was a Lithic Xeric Torriorthent of 30 cm depth. Three tillage systems were compared in Soil A: subsoiler tillage, minimum tillage and no-tillage, and two (minimum tillage and no-tillage) in Soil B. The experiment was repeated for 5 years on Soil A and 3 years on Soil B. Root length density, volumetric water content and dry matter were measured at important developmental stages. Yield was determined at harvest. In Soil A, root length density and volumetric water content were significantly greater for no-tillage than for subsoiler or minimum tillage (up to 1.4 cm cm⁻³ and 5%, respectively), mainly in the upper part of the soil profile. At lower depths, differences as great as 0.8 cm cm⁻³ and 6% were also found. Mean yield (4 years) was similar between no-tillage (3608 kg ha⁻¹) and minimum tillage (3508 kg ha⁻¹), and significantly smaller for subsoiler tillage (3371 kg ha⁻¹). In Soil B, no differences were observed between tillage systems for volumetric water content. Significant interactions between tillage and year were found for root length density, dry matter and yield. Mean yield (3 years) was not significantly different for minimum tillage (1806 kg ha⁻¹) and no-tillage (1867 kg ha⁻¹). The results in Soil A showed that surface conditions are of major importance in the water content of the soil and determined the differences among tillage systems. No-tillage favoured greater and deeper water accumulation in the soil profile and greater root growth. This makes this system potentially better for years of low rainfall. In Soil B no tillage system proved to be better because of the low water-holding capacity of this soil (56 mm).