Favorable Soil Temperature Research Articles

Sheepfolds induce significant increase of seasonal CO2, CH4 and N2O emissions in temperate steppes of Inner Mongolia

IntroductionThe changes in grassland management and grassland types are strongly linked with dynamics in soil physico-chemical properties and vegetation attributes, with important implications for carbon/nitrogen cycling and greenhouse gas (GHG) fluxes. However, the seasonal variations of GHG emissions from sheepfolds, and the underlying biotic and abiotic drivers affecting GHG exchanges across different steppe and management types remain largely unclear.MethodsTaking the Inner Mongolian grassland as a model system, we measured the fluxes of CO2, CH4 and N2O, as well as soil and vegetation variables, in three contrasting grassland management areas (grazing, sheepfold, enclosure) and in three representative (wet typical, dry typical, desert) grassland ecosystems in July, September and November 2016.ResultsOur results showed that: (1) GHG fluxes were mostly higher in the plant growing season (July and September) than in the nongrowing season (November); sheepfold area had significantly higher GHG emissions (in July and mean over the season) than enclosed and grazing areas, with the effects being most pronounced in dry typical steppe. (2) The high GHG emissions in dry typical steppe were closely associated with the interactions among favorable soil temperature and moisture, high total organic carbon (TOC) content, and high aboveground biomass. The important predictors for CO2 emission were soil TOC and pH, whereas that for CH4 and N2O emissions were soil temperature and moisture content, in sheepfold areas. (3) Three GHG emissions were negatively affected by species richness across all steppe and management types, which might be a consequence of indirect effects through the changes in soil TOC and total nitrogen (TN).DiscussionThese results indicate that sheepfold areas are intensive hotspot sources of GHGs in the steppes, and it is of great importance to help to account GHG emissions and develop mitigation strategies for sheepfold areas for sustainable grassland management in the natural steppe based pastoral production ecosystems.

Transforming microclimate to improve yield of cucumber (Cucumis sativus L.) by utilizing poly-house and colour plastic mulches associated with drip irrigation

Microclimate modification patterns are about the mimicking of natural systems to control the environment to achieve several benefits. Cucumbers (Cucumis sativus L.) are high yielding summer vegetables but are extremely sensitive to sudden weather changes. So, the changes in microclimatic parameters under polyhouse by using plastic mulching has evaluated on cucumber to improve the production of fruits and also to identify the optimum microclimatic situation of the crop. Research was conducted to study the performance of cucumber under protected conditions with different plastic mulches. This experiment was conducted in a split plot design, having irrigation levels as main plot and mulches as subplots. The study revealed that there was an increase in RH and air temperature inside the poly house. RH was increased by 8-12% that of outside. Temperature showed 5-7% increase in morning time and 7-10% in afternoon. Mulching helped to maintain the soil moisture higher than the bare soil and black mulch showed higher soil temperature and soil moisture (23.3%) under 100% irrigation. Black mulch with 100% irrigation attained maximum plant height (174.05cm). Yield of crop was also influenced by mulching. Black mulch with 100% irrigation attained maximum yield (36.1t/ha) followed by white (33.6t/ha) and silver (32.1t/ha) at same level of irrigation. Yield decreased in correspondence with reduction in irrigation level. Red and yellow mulches performed on par and maintained soil moisture greater than control plot. In conclusion, Black mulch with 100% irrigation performed well among the treatments because of higher moisture and favourable soil temperature.

Higher Temperature had Positive Effects on Seed Germination of Glycyrrhiza glabra under NaCl Stress

Background: Agricultural soils are affected by secondary salinization due to the fragile ecological environment and lack of scientific management. It is of interest to utilize the germplasm resources of salt-tolerant plants and improve their salinity stress resistance. Seed germination of the medicinal halophyte Glycyrrhiza glabra is affected by soil salt content and temperature during seeding. This study determined the favourable soil temperature for G. glabra seed germination in salinised soil. Methods: Four sodium chloride concentration gradients (control, hyposaline, medium-saline and hypersaline) and 3 temperatures (low- medium- and high temperature) were used for a total of 12 treatments; 30 seeds were utilised in each treatment and each treatment was repeated 3 times. Result: G. glabra seed germination indexes significantly decreased with increased salt concentration. Interestingly, higher temperature could improve the salt tolerance of seeds. Seed germination percentages of hyposaline, medium-saline and hypersaline treatments were higher at elevated temperature than those at low temperature by 33.53%, 127.1% and 41.7%, respectively and were higher than those at medium temperature by 14.1%, 121.6% and 54.6% respectively. Therefore, G. glabra seeds growing in saline habitats should be sown in summer. This study provided a scientific basis for medicinal plant cultivation in salinised soil.

Soil and Water Conservation Engineering Techniques to Modify the Rhizosphere Climate of Cucumber (Cucumis Sativus L.) for Improving Water Use Efficiency and Yield

Abstract The research was conducted to study the performance of cucumber under protected conditions with different plastic mulches. This experiment was conducted in a split plot design, having irrigation levels as main plot and mulches as subplots. The study revealed that mulching helped to maintain the soil moisture higher than bare soil and black mulch showed higher soil temperature and soil moisture (23.3%) under 100% irrigation. Plant height and yield was also influenced by mulching. Plant height and yield decreased in relation to reduction of the irrigation level. The highest water use efficiency (WUE) was found under 50% irrigation and black mulch plot (32 kg·m−3). In conclusion, black mulch with 100% irrigation performed well among the treatments because of higher moisture and favourable soil temperature. In consideration of WUE, black mulch with 50% irrigation performed well.

Straw strip mulching in a semiarid rainfed agroecosystem achieves winter wheat yields similar to those of full plastic mulching by optimizing the soil hydrothermal regime

Straw strip mulching (SM) is a new mulching technology. From 2012 to 2018, SM’s effects on soil moisture and temperature and production performances were compared with other mulching practices, using three treatments: full-cover plastic mulch (PM), no mulch with wheat sown in rows as the control (CK), and SM with 50% to 59% of the field area mulched. Compared with CK, on average over six growing seasons, SM and PM increased grain yield by 27.0% and 21.7%, straw yield by 21.6% and 22.6%, kernels ha−1 by 26.6% and 19.0%, net income by 29.8% and −25.0%, soil temperature at 5 cm by −1.5 °C and 0.2 °C from overwintering to maturity, and soil water storage at 0–200 cm by 25 and 22 mm, respectively. The increase in soil moisture in SM and PM was greater in the early period (overwintering to jointing) than in the later period (booting to maturity) and at 0 to 120 cm than at 120–200 cm in the early period. Although the mean evapotranspiration of whole growth period across six seasons was similar among treatments, SM and PM increased water consumption during the key formation period of yield components after overwintering by 16 and 32 mm, respectively, while reducing it before overwintering. Compared with CK, SM and PM had the effects of warming during overwintering and cooling after jointing. By increasing water consumption after overwintering and ratio of transpiration to evapotranspiration and providing favorable soil temperature for multiple growth stages and more sufficient soil moisture, SM and PM promoted vegetative growth and increased kernels ha−1, the main mechanisms by which SM and PM increased grain yield relative to CK. Relative to PM, SM is a more economically beneficial and environment-friendly technology for dryland wheat production.

Soil Temperature and Maize Nitrogen Uptake Improvement Under Partial Root-Zone Drying Irrigation

Soil temperature is a major effective factor on the soil and plant biological properties. Irrigation can affect soil temperature and thereby induces a temperature effect on plant growth, which may result in an economic increase due to higher yield and plant nutrition. A field experiment was carried out to investigate the effects of three irrigation strategies including full irrigation (FI), partial root-zone drying (PRD) and deficit irrigation (DI) on soil temperature and the consequent results on the grain yield and N uptake of maize (Zea May L.). Soil temperature was measured by time domain reflectometry (TDR) sensors during the 2010 growing season. Irrigation treatments were applied from 55 to 107 d after planting. The PRD treatment caused soil temperature to be in a favorable domain for a longer period (for over 60% of the measuring dates) as a consequent result of water movement to deeper soil layers compared with the other treatments; the PRD treatment also reduced soil temperature at deeper soil depths to below the maximum favorable soil temperature for maize root growth, which resulted in deeper root penetration due to both water availability and favorable soil temperature. Compared to the FI treatment, the PRD treatment increased root water uptake by 50% and caused no significant reduction in total N uptake, while this was not observed in the DI treatment partially due to the negative temperature effect of DI on plant growth, which consequently affected the water and nutrient uptake. A longer vegetation period in the PRD treatment was observed due to higher leaf N concentrations and no significant reduction in maize grain yield occurred in the PRD treatment, compared with those in the FI treatment. Based on the results, having 15.2% water saving during the whole growing season, the PRD irrigation would positively affect soil temperature and the water and nutrient uptake as a consequent, which thereby would prevent significant reduction in maize grain yield.

Quantitative Modeling of the Effects of Temperature and Inoculum Density of Fusarium oxysporum f. sp. ciceris Races 0 and 5 on Development of Fusarium Wilt in Chickpea Cultivars

ABSTRACT Races 0 (Foc-0) and 5 (Foc-5) of Fusarium oxysporum f. sp. ciceris differ in virulence and induce yellowing or wilting syndrome, respectively, in chickpea. We modeled the combined effects of soil temperature and inoculum density of Foc-0 and Foc-5 on disease developed in chickpea cvs. P-2245 and PV-61 differing in susceptibility to those races, using quantitative nonlinear models. Disease development over time in the temperature range of 10 to 30 degrees C and inoculum densities between 6 and 8,000 chlamydospores g(1) of soil was described by the Weibull function. Four response variables (the reciprocal incubation period, the final disease intensity, the standardized area under the disease progress curve, and the intrinsic rate of disease development) characterized the disease development. Response surface models that expressed the combined effect of inoculum density and temperature were developed by substituting the intrinsic rate of disease development in the Weibull or exponential functions with a beta function describing the relationship of response variables to temperature. The models estimated 22 to 26 degrees C as the most favorable soil temperature for infection of cvs. P-2245 and PV-61 by Foc-5, and 24 to 28 degrees C for infection of cv. P-2245 by Foc-0. At 10 degrees C, no disease developed except in cv. P-2245 inoculated with Foc-5. At optimum soil temperature, maximum disease intensity developed with Foc-5 and Foc-0 at 6 and 50 chlamydospores g(1) of soil respectively, in cv. P-2245, and with Foc-5 at 1,000 chlamydospores g(1) of soil in cv. PV-61. The models were used to construct risk threshold charts that can be used to estimate the potential risk of Fusarium wilt epidemics in a geographical area based on soil temperature, the race and inoculum density in soil, and the level of susceptibility of the chickpea cultivar.

Effect of black plastic mulch and raised bed on soil temperature and yield of sweet pepper

A field study was conducted in Central Hungary in 2001 and 2002 in order to evaluate the effects of black plastic mulch and raised bed on soil temperature and on yield and fruit quality of sweet pepper (Capsicum annuum L. cv. `Kárpia'). The experiment was a complete block design with four replicates. Four different technologies were used as treatments: raised bed with black PE mulch, raised bed without mulch, level ground with black PE mulch and level ground without mulch. In both years soil temperature was the highest in the covered raised bed treatment, about 2 °C higher than in the uncovered raised bed. Optimum soil temperature requirement of sweet pepper roots was met to the highest degree in case of the covered raised bed, 26-28% of the total growing period. The more favourable soil temperature conditions resulted in better yield, compared to the uncovered level ground treatment the covered raised bed treatment produced 19% and 14% higher yield in 2001 and 2002, respectively.

Growth, carbohydrate and nutrient allocation of Scots pine seedlings after exposure to simulated low soil temperature in spring

The effects of sustained low soil temperature on growth and allocation of biomass and carbohydrates in Scots pine (Pinus sylvestris L.) were studied by exposing 1-year-old seedlings to soil temperatures of 5 °C for 0, 3, 6 or 9 weeks and subsequently for 9 weeks at 13 °C. Growth at 5 °C soil temperature at the beginning of the growing season reduced the height of new shoots but the length of the cold soil period did not affect the final height. Some new root tips emerged during the 5 °C soil temperature period. Prolific root growth did not start until the soil temperature was increased from 5 to 13 °C, but new root growth was scarce during the first 3 weeks even at 13 °C, a clearly more favourable soil temperature than 5 °C. Seedlings exposed to a temperature exceeding 5 °C over any 3-week period during the first 9 weeks had above- and below-ground biomasses that were equivalent, whereas continual exposure to 5 °C reduced shoot and root growth. The above-ground biomass of the seedlings did not increase any more after Week 12, nor did the below-ground biomass after Week 15. Biomass allocation among the different parts of the seedlings was not greatly affected by the length of the cold soil period. Our results indicate that the accumulation of above-ground biomass is mainly dependent on the air temperature and not soil temperature. Element allocation followed the pattern of biomass allocation, except for N, which increased in the above-ground parts throughout the experiment, and Fe, which had already accumulated during the first 3 weeks. The seedlings grown for a longer time at low soil temperatures contained lower amounts of starch but similar amounts of soluble sugars throughout the experiment.

Soil nitrogen as affected by Gliricidia sepium in a silvopastoral system in Guadeloupe, French Antilles

Knowledge of the status and dynamics of soil N is essential to improving the production and management of silvopastoral system in the tropics. Soil N status and dynamics were analyzed as key factors affecting productivity and sustainability of a cut-and-carry silvopastoral system. The total soil N and N mineralization as affected by soil moisture and temperature were studied in a Gliricidia sepium (Jacq.) Walp – Dichanthium aristatum (Poir) C.E. Hubbard grassland association and in an adjacent open grassland located in a subhumid tropical region. The plot was installed in 1989 and the pruning residues and cut grass were removed from the site. No N fertilizer was applied. Total soil N increased at an average rate of 180 kg N ha−1 in the 0–0.2 m soil layer of the silvopastoral plot. Only a third of this value could be explained by the litter, nodule and root turnover. Nitrogen mineralization in both soils varied as a function of temperature but it was not affected by soil moisture. Even if mean soil temperature was 1 °C to 2 °C greater in the open grassland, the estimated daily rate of in-situ N mineralization was 20% greater in the silvopastoral system. Our results indicated that greater N mineralization in the silvopastoral system was due to greater soil biological activity associated with higher soil organic matter rather than due to more favorable soil temperature and water conditions.

Decomposition of 13C-labelled plant material in a European 65–40° latitudinal transect of coniferous forest soils: simulation of climate change by translocation of soils

Standard 13C-labelled plant material was exposed over 2–3 yr at 8 sites in a north–south climatic gradient of coniferous forest soils, developed on acid and calcareous parent materials in Western Europe. In addition to soils exposed in their sites of origin, replicate units containing labelled material were translocated in a cascade sequence southwards along the transect, to simulate the effects of climate warming on decomposition processes. The current Atlantic climate represented the most favourable soil temperature and moisture conditions for decomposition. Northward this climatic zone, where the soil processes are essentially temperature-limited, the prediction for a temperature increase of 3°C estimated a probable increase of C mineralisation by 20–25% for the boreal zone and 10% for the cool temperate zone. Southward the cool Atlantic climate zone, (the Mediterranean climate), where the processes are seasonally moisture-limited, the predicted increase of temperature by 1–2°C little affected the soil organic matter dynamics, because of the higher water deficit. A significant decrease of C mineralisation rates was observed only in the superficial layers recognised in Mediterranean forest soils as ‘xeromoder’ and subject to frequent dry conditions. In the deeper Mediterranean soil organic horizons (the mull humus types), representing the major C storage in this zone, C mineralisation was not affected by a simulated 2°C temperature increase. The temperature effect is probably counteracted by a higher water deficit.

Factors Limiting the Recruitment of Eucalyptus salmonophloia in Remnant Woodlands. III. Conditions Necessary for Seed Germination

Characteristics of the germination strategy of Eucalyptus salmonophloia are described, and whether the germination niche is limiting recruitment of E. salmonophloia seedlings in remnant woodlands is discussed. Germination in E. salmonophloia proceeds with favourable soil temperature and water conditions on a variety of substrates. However, at temperatures above and below the optimum for germination (25°C), enforced dormancy occurs and germination is retarded. In these situations, dormancy is simply overcome when temperatures return to optimum. Seeds can remain moist at sub-optimum temperatures for prolonged periods without losing viability. Furthermore E. salmonophloia seeds are capable of withstanding a cycle of wetting and drying with undiminished germination capacity. Conditions suitable for germination occur at the beginning of the winter wet season in SW Australia when soil temperatures are still suitable and soil moisture and atmospheric humidity are frequently high. These germination characteristics minimize the chances of seeds germinating at times when the probability of seedling establishment is low (e.g. summer). This is particularly important because E. salmonophloia only establishes a temporary soil, seed-reserve following large scale disturbances, and therefore the opportunities for recruitment may be quite rare. In remnant woodland when ants were excluded and a soil seed-bank was created artificially, seeds germinated, but no seedlings survived. This suggests that the destruction of seeds by ants during inter-disturbance periods is having little effect on recruitment because seedlings are unlikely to establish. Unfavourable conditions for germination are unlikely to be responsible for the lack of E. salmonophloia seedling recruitment in remnant woodlands.Further research is needed to identify the factors critical for seedling establishment; changes in resource availability following large-scale disturbances and associated tree death are important in this respect.

Regional Variation in the Seasonal Activity of the Imported Fire Ant, Solenopsis saevissima richteri1

Studies were conducted over a one-year period at 6 locations throughout the range of the imported fire ant, Solenopsis saevissima richteri Forel, to determine regional variations in the seasonal activity of this pest. Threshold levels for various types of activity were found to be uniformly temperature-dependent in all parts of the range. Workers began to forage when soil temperatures exceeded 10°C. Some foraging occurred even in the winter months in the northern part of its range when the daily temperature exceeded this threshold for more than a few hours. Brood production in spring began when the weekly mean soil temperature (at 5 cm) rose above 10°C, worker and sexual pupae appeared at ca. 20°C, and the alates at 22.5°C. In Florida the period of favorable soil temperature for new colony-founding and growth (24°C) lasted ca. 198 days; in northern Mississippi it lasted 83 days. Similarly, the ants in Florida were found to consume twice as much food annually and to produce 1.5 times more brood than the ants in the northern part of the range.

EFFECTS OF HEATING AND INSULATING SOIL ON CORN GROWTH

Interacting effects of controlled heat from electric heating cables 15 cm below the surface and of polystyrene insulation on the soil surface were studied over four seasons on an imperfectly drained outwash soil at Guelph, Canada. Heating to 22 C advanced germination of corn (Zea mays L.) by three days, improved emergence, advanced growth and increased yield at maturity. Insulation retarded germination, early growth and silking, but increased yields in three of the four years. Where heating decreased ear moisture content at harvest, insulation increased it. Heat combined with insulation gave the greatest response in growth, advance in silking, and increase in yield. The season with favorable soil temperature combined with low air temperature gave the highest yield of the four years. Fertilizer banded near the seed at planting advanced development and increased yields, but did not produce a statistically significant interacting effect with heat and insulation. However, fertilizer phosphorus uptake early in the season was markedly increased by heat and insulation. It was concluded that insulation can favor yield, provided that soil temperature is maintained near optimum.

GROWTH AND YIELD OF OATS AS INFLUENCED BY SOIL TEMPERATURE, AMBIENT TEMPERATURE AND SOIL MOISTURE SUPPLY

Oats were grown in the greenhouse under four soil moisture regimes at each of several combinations of aerial and soil temperatures. In one series of experiments, both air and soil temperature was controlled at 13, 18.5 and 24 °C. A second series involved the same soil temperatures but a single air temperature (18.5 °C) was common to all soil temperatures. Air and soil temperatures higher than 13 °C reduced yield more drastically than soil temperatures above 13 °C. It is suggested that high air temperature placed a restriction on root growth that was not offset by the most favorable soil temperature employed. High temperatures and high levels of soil moisture increased the rate of stem elongation and the height at heading but reduced the time between emergence and heading. Increased height which resulted from high levels of moisture increased yield, but increased height resulting from high temperature was associated with reduced yield.

Corn Growth as Affected by Soil Temperature and Mulch1

SypnosisIncreases in soil temperature accelerated rate of emergence, rate of growth, and promoted earliness in corn. Corn growth rates approximately followed the Van't Hoff law, the Q10° c. of that law being from 2.0 to 2.8 for the average temperature range tested, 60° to 80° F. Corn yields appeared to increase with increases in soil temperature up to a point and then decreased with further increases in soil temperature. The most favorable soil temperature at the 4‐inch depth for corn growth in central Iowa appears to be about 75° F.