Average Soil Temperature Research Articles

Different mulching materials influence the reclamation of saline soil and growth of the Lycium barbarum L. under drip-irrigation in saline wasteland in northwest China

The plastic mulch has been widely used for salinity controlling in arid-saline area for decades, but the residual plastic shows serious hazards to human and environmental health nowadays. To find an alternative from potential materials, a mulching experiment consisting of 4 treatments, the sown grass cover (GC), the black plastic film (BF), the straw curtain (SC), and the bare soil (CK), for the Lycium barbarum L. (LL) cultivation was conducted for 2 years. The soil physical and chemical parameters and LL responses were comprehensively evaluated. Results showed the average soil water content during a single irrigation interval was the highest in BF, followed by SC and CK that were comparable, and the lowest in GC in both years. The average soil temperatures within 0–20 cm depth in midsummer in BF was 4.1, 4.5 and 1.9 ℃ higher than those in SC, GC and CK, respectively. The soil desalination rates in GC, BF, SC and CK were 47.9%, 46.5%, 66.2% and 45.0% when compared with the initial salinity in the first year. And those became 43.6%, 82.5%, 73.5% and 76.4% when the second year terminated. The growing parameters of the LL in SC and CK were significantly larger than other treatments. The high soil temperature in BF and the water competition of sown grass in GC had adverse effects on the survival rate, growth, and photosynthetic efficiency of the LL, resulting in the yields and irrigation water productivities (IWP) in BF and GC being 45.8% and 46.3% lower than CK, respectively. While the yield and IWP in SC were 26.9% higher than CK. Considering the changes of soil parameter and LL response comprehensively, the straw curtain could be the best alternative of plastic film for the LL cultivation in saline soil in low-lying arid area.

Effects of small ridge and furrow mulching degradable film on dry direct seeded rice

Global climate change and socio-economic development have led to a shortage of water and labour resources, which has had a significant impact on rice cultivation. In this study, the application of micro-ridge-furrow planting technology and degradable film mulching in dry direct-seeded rice was investigated to address the factors restricting the development of the rice industry and reduce the impact of rice production on the environment. The effects of a micro-ridge-furrow planting pattern and degradable film mulching on soil temperature, seedling growth, and yield of dry direct-seeded rice in a semiarid region of China were studied through three field experiments: micro-ridge-furrow mulching with traditional plastic film (T1); micro-ridge-furrow mulching with degradable film (T2); and traditional flat-cropping mulching with traditional plastic film (CK). The experimental results demonstrated that the micro-ridge-furrow mulching film planting pattern promoted the germination of rice seeds and improved the soil temperature, plant height, leaf area, dry mass, and grain yield. T2 had the highest average soil temperature (14.68–17.83 ℃ during the day; 14.4–15.74 ℃ at night), leaf area (41.85 cm2 plant−1), root dry mass (45.32 mg plant−1), shoot dry mass (58.46 mg plant−1), root–shoot ratio (0.821), and yield (8.112 t ha−1). In summary, the micro-ridge-furrow mulching with degradable film (T2) is recommended as an efficient planting and mulching pattern for sustainably solving environmental problems and improving grain yield in semiarid regions of China.

Effects of photovoltaic panels on soil temperature and moisture in desert areas.

Photovoltaic power generation is an important clean energy alternative to fossil fuels. To reduce CO2 emissions, the Chinese government has ordered the construction of a large number of photovoltaic (PV) panels to generate power in the past two decades; many are located in desert areas because of the sufficient light conditions. Large-scale PV construction in desert areas can alter the local microclimate and soil conditions, thereby affecting the growth of vegetation. However, few studies have focused on the effects of PV panels on the environment of desert areas. In this study, we investigated the effects of PV panels on soil moisture and temperature via a whole-year field experiment at a PV power plant in a desert area in western China. The in situ soil moisture and temperature at a depth of 0-0.4 m were measured under three types of PV shading conditions: shaded by fixed-tilt (FIX) PV panels, shaded by oblique single-axis (OSA) PV panels, and no shading. The results showed that the soil temperature and moisture at sites under PV shading were significantly affected compared with those at sites without shading. PV panels increased the average soil temperature during winter but decreased it during the other three seasons. Moreover, the warming effect of FIX PV panels on the soil is more apparent than that of OSA PV panels. PV panels have positive effects on soil moisture. Compared with that at the sites without shaded areas, the average soil moisture under the FIX PV panels and under the OSA PV panels increased by 14.7% and by 11.1%, respectively. These data provide support for future studies on vegetation restoration around PV power plants in desert areas.

К ВОПРОСУ ИЗУЧЕНИЯ ТЕМПЕРАТУРНОГО РЕЖИМА ПОЧВ ЗАПОВЕДНИКА «БАСТАК» НА ОСНОВЕ ИСПОЛЬЗОВАНИЯ ПРОФЕССИОНАЛЬНОЙ МЕТЕОСТАНЦИИ «СОКОЛ-М»

The paper presents the experience of using data on soil temperature obtained with the help of a professional weather station «Sokol-M» in the Bastak nature reserve. The author has made the analysis of average daily air and soil temperature indicators at different depths. The process of heat propagation deep into the soil is observed, due to the absence of negative soil temperatures at a depth of 25 cm, with negative indicators in the upper 10 cm of the soil profile.

Integration of soil solarization with bio-control agents for the management of stem rot of chrysanthemum

A study was conducted during 2016 at Nauni to find out the Effect of soil solarization with transparent polyethylene mulch (25µm thick) was recorded on soil temperature in the earthen pots and pathogenic potential of the stem rot pathogen mixed in the soil of the earthen pots. Soil solarization increased average maximum soil temperature to 45.9 °C, with an increase of 7.8 °C at 5 cm soil depth over unsolarized pots. Effect of combination of soil solarization and biocontrol agents was also observed on disease causing capability of the Rhizoctonia stem rot pathogen. Trichoderma viride was found most effective with no incidence of the disease and this treatment combination reduced the viability of the sclerotia by 99.2 per cent in comparison to unsolarized control.

White Plastic and Deficit Irrigation Improve Pomegranate Production

ABSTRACT Developing improved water management strategies and on-farm cultural practices are important in reducing pomegranate (Punica granatum L. cv Wonderful) production costs. A pomegranate orchard established in 2010 was irrigated at water replacement rates of 35, 50 and 100% of crop evapotranspiration from 2013 to 2016. A durable white plastic tarp was installed in one half of each water replacement plot to evaluate the added benefits to soil moisture retention, weed control, and plant growth and yield. Edaphic orchard floor conditions such as light reflectance into the lower tree canopy, mid-day soil surface temperature, soil water content, and average daily soil temperatures were moderated or improved by the plastic cover. Phenological changes such as leaf greenness, trunk basal suckering, and trunk diameter were generally enhanced by increased water application rates and plastic use. Marketable and total fruit yields increased by an average of 20 to 29% from 2013 to 2016 with the use of plastic cover compared to bare soil. Total fruit yield increased linearly with increasing water replacement rates. Neither the white plastic nor irrigation rates improved external fruit color. Fruit raw product attributes were little changed by treatments. The research clearly demonstrated the benefit of plastic cover on improving pomegranate production.

Effect of soil solarization on viability, disease incidence and incubation period of stem rot of chrysanthemum caused by R. solani

A study conducted during 2016 at Nauni to find out the effect of soil solarization with transparent polyethylene mulch (25µm thick) was recorded on soil temperature in the earthen pots and pathogenic potential of the stem rot pathogen mixed in the soil of the earthen pots. Soil solarization increased average maximum soil temperature to 45.9 °C, in the year 2016 with an increase of 7.8 °C at 5 cm soil depth over unsolarized pots. Soil solarization for 40 days resulted in significant reduction in the potential of the pathogen to cause the disease. Soil solarization was observed on disease causing capability of the stem rot pathogen. Sclerotia of Rhizoctonia stem rot pathogen subjected to soil solarization with transparent polyethylene sheet which were put at 5 cm soil depth for 40 days lost the viability of by 88.7 per cent in comparison to unsolarized soil in the pots. Sclerotia of the stem rot pathogen subjected to soil solarization with transparent polyethylene sheet at 5 cm soil depth for 40 days increased the incubation period of the disease by 21.2 per cent i.e. symptoms were delayed and reduced the disease incidence by 46.1 per cent in comparison to unsolarized pots.

Effect of Soil Solarization and Bio-fertilization on Strawberry Production and pathogenic Fungi under Siwa Oases Conditions

The present study was carried out during the two successive seasons of 2017-2018 and 2018-2019 in the experimental station, desert research center at Siwa oasis, Marsa Matrouh Governorate to evaluate the effect of soil solarization and bio-fertilization on soil borne microorganisms, weed characters, growth, yield and quality of strawberry. The experiment included two solarization treatments (solarize and non-solarize) and five bio-fertilizers treatments (Bio-fertilizers alone, bio-fertilizers + 0.25 mineral fertilizers, bio-fertilizers + 0.5 mineral fertilizers, bio-fertilizers + 0.75 mineral fertilizers as well as the traditional treatment as a control. The results indicated that, soil solarization increased average soil temperature and eradicated most annual broad and narrow-leaved weeds, increased microorganisms population and reduced rotted fruit caused by pythium or phytophthora as well as increasing of strawberry growth early yield and yield. Traditional treatment produced the highest yield followed by bio-fertilizers treatments with 0.75, 0.50 and 0.25 percent of chemical fertilizers compared with bio-fertilzers alone. On the other hand, bio- fertilizers produced the highest fruit quality and gave the lowest values of rotted fruits.

Mechanism of Photothermal Energy on the Growth and Yield of Rice under Water Level Regulation

The flooding caused by heavy rainfall in rice irrigation area and the drought caused by the drop of groundwater level are the research focus in the field of irrigation and drainage. Based on the comparative experiment and farmland water level control technology, this paper studied the average soil temperature under different soil layers (TM), the daily temperature change (TDC), the photosynthetic accumulation of single leaf and canopy in rice, and response of photothermal energy to rice root characteristics and growth factors in the paddy field under drought conditions. The results showed that the peak soil temperature under drought treatment was basically synchronous with the conventional irrigation, and the it was delayed by 2–6 h under flooding treatment compared to the drought treatment. Under different water gradients, the temperature decreased according to TL > TCK > TH (L, H and CK represented water flooding, drought and control treatments), and the TDC was opposite. In addition to milky stage, the daily photosynthetic (Pn) accumulation of single leaf and canopy in the flooding and drought treated paddy fields were lower than conventional irrigation, and had a negative impact on leaf area index (LAI) and yield (YR), but did not form fatal damage. The root characteristic factors, RL (root length), RW (root weight), R-CR (root-canopy ratio) were promoted with drought, and YR under light drought was slightly higher than that under heavy drought. There was a strong positive correlation between TM and R-CR in all rice growth stages, while TDC-5 was negatively correlated with effective panicle number, TDC and R-CR in 20 cm soil layer were positively correlated. The correlation between daily Pn accumulation and YR was low, and the correlation between Pn and YR factors was negative or weak positive or negative. The total Pn was positively correlated with yield factors, and the correlation coefficient was higher than that of daily Pn.

Mosses reduce soil nitrogen availability in a subarctic birch forest via effects on soil thermal regime and sequestration of deposited nitrogen.

In high‐latitude ecosystems bryophytes are important drivers of ecosystem functions. Alterations in abundance of mosses due to global change may thus strongly influence carbon (C) and nitrogen (N) cycling and hence cause feedback on climate. The effects of mosses on soil microbial activity are, however, still poorly understood. Our study aims at elucidating how and by which mechanisms bryophytes influence microbial decomposition processes of soil organic matter and thus soil nutrient availability.We present results from a field experiment in a subarctic birch forest in northern Sweden, where we partly removed the moss cover and replaced it with an artificial soil cover for simulating moss effects on soil temperature and moisture. We combined this with a fertilization experiment with 15N‐labelled N for analysing the effects of moss N sequestration on soil processes.Our results demonstrate the capacity of mosses to reduce soil N availability and retard N cycling. The comparison with artificial soil cover plots suggests that the effect of mosses on N cycling is linked to the thermal insulation capacity of mosses causing low average soil temperature in summer and strongly reduced soil temperature fluctuations, the latter also leading to a decreased frequency of freeze‐thaw events in autumn and spring. Our results also showed, however, that the negative temperature effect of mosses on soil microbial activity was in part compensated by stimulatory effects of the moss layer, possibly linked to leaching of labile substrates from the moss. Furthermore, our results revealed that bryophytes efficiently sequester added N from wet deposition and thus prevent effects of increased atmospheric N deposition on soil N availability and soil processes. Synthesis. Our study emphasizes the important role of mosses in carbon and nutrient cycling in high‐latitude ecosystems and the potential strong impacts of reductions in moss abundance on microbial decomposition processes and nutrient availability in subarctic and boreal forests.

Application of biodegradable plastic mulch improves manure N availability and tomato yield in an organic cropping system

Low crop yield in organic farming restricts its popularization, and N deficiency is one of important reasons for the yield decline in organic farming. In this study, the biodegradable plastic mulch (BDP) was introduced into organic farming and its effects on soil N mineralization and crop yield were investigated. Over the two experimental years, application of manure + BDP improved the average soil moisture by 1.3% and 1.1%, and average soil temperature by 1.8 °C and 0.8 °C, and led to 27% and 26% higher cumulative mineralized N. Additionally, tomato fruit yield was improved by 18% and 18%, NUE increased by 104% and 77%, and N recovery rate greater by 60% and 48% in 2 years, respectively. Improvement of cumulative mineralized N was significantly correlated with soil temperature, while has no significant relationship with soil moisture. However, the tomato yield was obviously correlated with soil moisture, soil temperature, and N mineralization. This study suggested that the application of Manure + BDP improves the tomato yield due to its improvement on soil temperature, soil moisture, and accumulated mineralized N in organic tomato farming and implies that Manure + BDP can be considered as an option to improve the tomato yield in organic farming systems.

Plastic Film Mulch Performed Better in Improving Heat Conditions and Drip Irrigated Potato Growth in Northwest China than in Eastern China

Plastic film (i.e., transparent and black films) is widely applied in mulching to improve thermal environments and plant growth in China. However, choosing suitable film for potato cultivation in different areas is still a problem. A four-year field experiment was conducted to explore the influences of plastic mulch on heat transfer (soil heat flux, G; soil temperature; and canopy net radiation, Rn) and potato growth in two typical areas of China: Experiment 1 in Northwest China (2014 and 2015) and Experiment 2 in Eastern China (2016 and 2017). Three mulch treatments were designed as follows: (1) transparent film (TF), (2) black film (BF), and (3) no film (NF). Results showed that the Rn and G differences between TF, BF, and NF varied at different areas. However, the Rn in TF was always smaller (average 12.4 W/m2 in 2014–2017) than in BF in the two study areas. The differences of soil temperature between TF, BF, and NF in Experiment 1 were greater than in Experiment 2. The average soil temperature difference between TF and NF was 1.4 °C higher in Experiment 1 than in Experiment 2. TF had 23% and 19% more jumbo tubers than BF in weight and number on average with no significant difference in 2015–2017. TF and BF significantly had greater potato yield and irrigation water use efficiency than NF on average in Experiment 1, while no significant differences were found in Experiment 2. The transparent film was more beneficial to increase soil temperature and jumbo tubers than the black film. Film mulch functioned better for improving heat conditions and drip-irrigated potato growth in Northwest China than in Eastern China.

Screening of advanced breeding lines for high temperature tolerance using biochemical parameters in Indian mustard (Brassica juncea)

A set of 30 advanced breeding lines of Brassica juncea were screened for heat tolerance in terms of biochemical parameters in field condition at ICAR-DRMR. The selection was based on (1) early sowing (ES) (September) when average soil temperature was 41ᵒC and atmospheric temperature was around 35ºC so that heat stress coincided with seedling growth and (2) normal sown (NS) (mid October) where soil temperature was 34.2ᵒC so that seedling growth did not coincide with any stress. Various biochemical parameters like total chlorophyll, total carotenoid content, total antioxidant capacity, radical scavenging activity, lipid peroxidation and proline content were measured in leaves at flowering stage to evaluate the variability among the genotypes and comparison between ES and NS was done. Stress susceptibility index (SSI) categorized genotype NPJ-124 and DRMR-1165-40 to be highly tolerant. Correlation analysis among all the traits showed total antioxidant capacity to be significantly correlated to carotenoids and chlorophyll pigment levels showing the importance of these parameters as indices for screening.

Thermal physiology explains the elevational range for a lizard, Eutropis longicaudata, in Taiwan.

1: The decrease of temperatures along an elevation gradient imposes physiological constraints on reptiles that ultimately determine their distribution ranges. Forest patterns are likely to interact with this process, but very few studies have examined their contribution in determining distribution limits. 2: We examined the role played by thermal physiology and forest cover in determining the elevational ranges of a lizard, Eutropis longicaudata. We integrated this species' thermal traits in simulating its maximum activity time under different conditions of forest cover and elevation using a NicheMapR model. In addition, we evaluated the influence of winter temperatures on the range limit by examining the simulated soil temperatures at the occurrence sites. 3: Laboratory experiments showed that E. longicaudata has a high preferred body temperature and low cold tolerance. The model predicts that maximum activity time decreases with elevation and forest cover. Although unforested areas may provide longer active time in all simulated elevations, mountain areas in Taiwan are heavily forested and are predicted to allow only a very short period of activity above 1000m elevation. 4: All sightings were indeed located in areas below 1000m elevation, in which the predicted average soil temperature is above 10°C in January in cold years. 5: Our results show that reptile physiological response does respond strongly to the change of microclimate induced by forest cover and elevation. Overall, this suggests that forest cover is a major determinant of some reptiles' elevational range.

Effects of straw biochar application on soil temperature, available nitrogen and growth of corn

Straw biochar could improve the water holding capacity effectivity of salinized soil, increase soil fertili, enhance crop yield, reduce greenhouse gas emission, and mitigate climate change. The mechanism of using straw biochar for soil improvement is different under various climate and soil texture conditions. To explore the mechanism of using straw biochar to improve soil and its influence on crop yield in the typical arid and semi-arid, a large temperature difference between day and night, soil temperature at different depths, and physiological changes and crop yield of maize at different growth stages were studied. It is assumed that straw biochar can improve the properties of salinized soil including physicochemical indexes, and crop physiological index, stimulates the positive circulation between soil, vegetation, and microorganisms, and plays a role in improving soil quality. The results showed that biochar application increased the average soil temperature (T) by 2 °C and reduced day-night T differences. Application of 30 t/ha biochar increased the average maize leaf T by 2.2 °C and photosynthetic rate by 16.5%. Furthermore, the average transpiration rate doubled compared to control, and the chlorophyll value increased by 21%. The application of biochar improved the utilization rate of nitrogen fertilizer by enhancing ammonification. Biochar application caused a maximum overall yield increase of 11.9% compared to control treatment (CK). Therefore, these results provide a practical basis for improving weakly alkaline farmland soils in arid and semi-arid areas, and provide an effective method to potentially mitigate the environmental crisis and promote sustainable development in agriculture.

Effects of micro-ridge-furrow with plastic mulching and bunching seeding on soil hydrothermal environment and its response to photosynthesis and grain yield of spring wheat

The relieving of drought and cold restriction on spring wheat development is one of the key factors increasing wheat yield in arid areas of central Gansu Province. A field experiment with spring wheat (Longchun No. 35) was carried out in central Gansu Province from 2016 to 2018. There were three treatments: 1) micro-ridge-furrow with whole field plastic mulching and bunching seeding (PRF), 2) whole field soil plastic mulching and bunching seeding (PMS), 3) bunching seeding without mulching (CK). We measured soil temperature in 0-25 cm profile, soil water content in 0-300 cm profile, leaf SPAD, photosynthetic rate, transpiration rate, aboveground biomass in different growth stages, and grain yield to understand the effect of PRF on soil hydrothermal environment, spring wheat yield and water use efficiency (WUE) from the aspect of soil hydrothermal, canopy development and grain yield. The results showed that mean soil temperature in 0-25 cm profile of PRF and PMS increased by 2.8 ℃ and 2.5 ℃ at the seedling stage, decreased by 1.4 ℃ and 0.9 ℃ from filling to maturity stage, respectively. Soil water storage in 0-300 cm profile of PRF and PMS increased by 59.7 mm and 41.8 mm from sowing to seedling stage. Water consumption of PRF and PMS increased by 46.1 mm and 39.8 mm from seedling to filling stage. PRF increased average soil temperature in 0-25 cm profile by 0.3 ℃ at seedling stage, but decreased by 0.5 ℃ from filling to maturity stage, and increased soil water storage in 0-300 cm profile by 18.0 mm from sowing to seedling stage. PMF increased water consumption by 13.0 mm from booting to maturing stage, as compared with PMS. Based on the optimizated soil hydrothermal conditions, leaf SPAD value, aboveground biomass, net photosynthetic rate, and transpiration rate of PRF increased, as compared with PMS and CK. The PRF increased grain yield by 9.1% and 36.5%, WUE by 5.9% and 30.8% compared to PMS and CK, respectively. Consequently, PRF increased soil temperature at wheat seedling stage, reduced it from filling to maturing stage, improved wheat water consumption from sowing to filling stage, increased leaf SPAD value and aboveground biomass, promoted photosynthetic function in leaf from seedling to filling stage, and consequently led to increased yield and water utilization. Such effects were more significant in dry year (2016 and 2017).

EFFECT OF MULCH ON SOIL TEMPERATURE, SOIL MOISTURE CONSERVATION AND YIELD OF CHILLI

The experiment was conducted at Regional Agricultural Research Station (RARS), Jamalpur, Bangladesh during the period of 2017-18 and 2018-19 with the objectives to evaluate the effect of different mulch on soil temperature, soil moisture conservation and yield attributes of chilli. There were five treatments comprising T1: no mulch, T2: rice straw mulch @ 5 t ha-1, T3: water hyacinth mulch @ 5 t ha-1, T4: black polyethylene mulch and T5: white polyethylene mulch. The results revealed that, all the mulch treatment had higher soil temperature and soil moisture content at 5 cm and 10 cm depth compared to no mulch treatment. Soil temperature was highest in black polyethylene mulch, it increased average soil temperature by about 5.7 oC at 5 cm depth and 5.1 oC at 10 cm depth compared to no mulch treatment at 120 Days. Rice straw mulch treatment recorded highest soil moisture, it increased average soil moisture about 27.87 % at 5 cm depth and 28.57% at 10 cm depth over no mulch treatment. Rice straw mulch treatment produced highest green chilli yield (8.81 t ha-1) which was 26.94 % increased over no mulch treatment (6.94 t ha-1).Considering economic analysis, highest gross return (Tk 352400 ha-1), gross margin (Tk 235400 ha-1) and BCR (3.01) was obtained from same treatment T2 i.e., rice straw mulch treatment.

Effect of organic mulches on agronomic parameters – a case study of tomato crop (Lycopersicon esculentum Mill.)

Purpose ThePresent study was conducted to investigate the effectiveness of locally available organic mulches on moisture retention, yield and irrigation water use efficiency in tomato crop. Methods The crop was grown in a randomized complete block design using pine needle mulch, wheat straw mulch and rice straw mulch as treatments and no mulch serving as control. Results Mulches were able to increase the soil moisture retention through 0.1 m to 0.5 m soil depth. Though mulches behaved differently in soil moisture retention at various depths, the average moisture retention observed for pine needle mulch, rice straw mulch, wheat straw mulch and no mulch was 22.18 %, 21.01 %, 18.52 % and 18.23 %, respectively. The mulches brought about a soil temperature reduction to an extent of 3.3 °C in maximum daily temperature and 1.4-1.8 °C in average soil temperature at 14:00 o'clock during the crop period. The positive effect produced on soil hydrothermal environment was directly reflected through increased leaf area index, plant height and yield. The trend of favourable effect produced by mulches on growth parameters was pine needle mulch > rice straw mulch > wheat straw mulch > no mulch. Mulching increased irrigation water use efficiency by 28.9%, 26.6 % and 12.5 % in pine needle mulch, rice straw mulch and wheat straw mulch, respectively over no mulch. Conclusion Locally available organic materials can effectively be used to increase soil moisture retention, enhance yield and irrigation water use efficiency in tomato crop.

Effects of biodegradable mulch on soil water and heat conditions, yield and quality of processing tomatoes by drip irrigation

To combat the problem of residual film pollution and ensure the sustainable development of agriculture in oasis areas, a field experiment was carried out in 2019 at the Wuyi Farm Corps Irrigation Center Test Station in Urumqi, Northwest China. Four types of biodegradable mulches, traditional plastic mulchs and a control group (bare land; referred to as CK) were compared, including a total of six different treatments. Effects of mulching on soil water and heat conditions as well as the yield and quality of processing tomatoes under drip irrigation were examined. In addition, a comparative analysis of economic benefits of biodegradable mulches was performed. Principal component analysis and gray correlation analysis were used to evaluate suitable mulching varieties for planting processing tomatoes under drip irrigation. Our results show that, compared with CK, biodegradable mulches and traditional plastic mulch have a similar effect on retaining soil moisture at the seedling stage but significantly increase soil moisture by 0.5%–1.5% and 1.5%–3.0% in the middle and late growth periods (P<0.050), respectively. The difference in the thermal insulation effect between biodegradable mulch and plastic mulch gradually reduces as the crop grows. Compared with plastic mulch, the average soil temperature at 5–20 cm depth under biodegradable mulches is significantly lowered by 2.04°C–3.52°C and 0.52°C–0.88°C (P<0.050) at the seedling stage and the full growth period, respectively, and the water use efficiency, average fruit yield, and production-investment ratio under biodegradable mulches were reduced by 0.89%–6.63%, 3.39%–8.69%, and 0.51%–6.33% (P<0.050), respectively. The comprehensive evaluation analysis suggests that the black oxidized biological double-degradation ecological mulch made from eco-benign plastic is the optimal film type under the study condition. Therefore, from the perspective of sustainable development, biodegradable mulch is a competitive alternative to plastic mulch for large-scale tomato production under drip irrigation in the oasis.

Impacts of ammonia volatilization from broadcast urea on winter wheat production

AbstractAmmonia (NH3) volatilization from broadcast urea may lead to significant N losses in winter wheat. We aimed to: (a) quantify N losses through NH3 volatilization from fields fertilized with urea and urea amended with a urease inhibitor (NBPT) under cold weather months (February–April), and (b) investigate the impact of N losses through NH3 volatilization on the winter wheat production. We employed the integrated horizontal flux (IHF) method with passive NH3 samplers to quantify NH3 volatilization at five sites in Kansas. Urea and urea + NBPT were broadcast at a rate of 60 kg N ha–1 over circular plots. We assessed the impact of NH3 losses on wheat at three sites employing different rates of urea and urea + NBPT. NH3 losses volatilization varied from 0.3 to 29.6% of total N applied. The largest N losses (&gt;23% of applied N) occurred when urea was broadcasted to moist soils followed by a dry period. Amending urea with NBPT reduced NH3 volatilization losses by more than 20% on the campaigns with the largest N losses (&gt;23%). However, our results showed no significant differences for wheat yield, N‐recovery and agronomic efficiency between urea and urea + NBPT treatments likely due to the reduced NH3 volatilization (&lt;17%) where the impact on winter wheat was measured. Our results suggest that winter wheat farmers should carefully evaluate the soil surface moisture conditions before broadcasting urea to avoid potential NH3 volatilization losses even under cold conditions (average soil temperature ranging from 2.5 to 7.7 °C).