•Soil water under the PM treatment was higher than that under the SM treatment.•Compared with CK, plastic film mulching and straw mulching increased MBC and MBN concentrations.•Compared with CK, ...straw mulching increased DOC and DON, but plastic film mulching decreased DOC and DON.•The average water use efficiencies under mulching practices were higher than that under the CK treatment.
A field experiment was conducted in the Loess Plateau of Northwest China to study the effects of plastic film mulching and straw mulching on soil water, soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) and nitrogen (MBN), dissolved organic carbon (DOC) and nitrogen (DON), crop yield and water use efficiency under winter wheat (Tricicum aestivum L.)—summer maize (Zea mays L.) double-cropping system conditions using the following three cultural practices: (i) traditional plough with no mulching (CK), (ii) traditional plough with plastic film mulching (PM), and (iii) traditional plough with straw mulching (SM). Soil water contents were measured by the gravimetric method. SOC was determined using the dichromate oxidation method. TN was analyzed by the Kjeldahl method. MBC and MBN were determined using the chloroform fumigation extraction method. DOC and TDN were determined following Jones’ procedures proposed by Jones and Willett (2006). The results showed that soil water was higher under the PM treatment than under the SM treatment and mainly changed in the upper 60 cm soil layer. Compared with the CK treatment, the concentrations of SOC and TN under the SM treatment were increased by 16.9% and 7.7% at the 0–10 cm soil depth, respectively, and the PM treatment had the similar SOC and TN concentrations. Compared with the CK treatment, soil C:N ratio was increased under the SM treatment by 6.2% (P < 0.05), and that under the PM treatment was decreased by 5.2% (P < 0.05) after three years. The concentrations of MBC under the PM and SM treatments were significantly increased by 42.0% and 24.1%, respectively, and MBN under the PM treatment was significantly increased by 5.6% at 0–10 cm soil depth after the maize season. Compared with the CK treatment, DOC was significantly increased by 21.0% under the SM treatment and decreased by 13.1% under the PM treatment, and DON was significantly increased by 10.5% under the SM treatment and decreased by 4.3% under the PM treatment at the 0–10 cm soil depth after the maize season. Relative changes of labile soil organic carbon and nitrogen fractions were more sensitive than that of SOC and TN. The relative decline or increase of labile soil organic carbon and nitrogen fractions was on average almost 13.6% for the mulching practices. Compared with the CK treatment, the average maize yields under the PM and SM treatments were increased by 26.4% and 9.8%, and the average wheat yields under the PM and SM treatments were increased by 21.3% and 7.4%, respectively. The average water use efficiencies under the PM and SM treatments were 24.5%, 8.8% in winter wheat and 22.9%, 6.3% in summer maize higher than that under the CK treatment, respectively. Our results suggested that plastic film mulching could be used as an effective practice to improve low soil quality with adequate nitrogen and increase crop yield and water use efficiency in the Loess Plateau, China.
The ridge-furrow mulching system (RFMS) is widely used to improve crop yields and water use efficiency in arid and semi-arid rainfed agricultural regions. However, the effects of RFMS on hydrothermal ...states and maize (Zea mays L.) yields in dry sub-humid regions remain unclear. The objective of this study was to determine the influence of ridge-furrow construction and plastic film mulching on soil moisture and temperature, evapotranspiration (ET), maize growth and yield, water use efficiency (WUE), and thermal time use efficiency (TUE) in dry sub-humid regions of the Loess Plateau. A three-year field study was conducted in which four different planting practices were evaluated: (1) alternating wide ridges and narrow furrows with film mulching (WRM), (2) alternating equal-width ridges and furrows with film mulching (ERM), (3) equal row spacing in flat plot with half film mulching (EFM), and (4) conventional flat plot without mulching (CK). The results demonstrated that at early maize growth stages, soil water storage within the 0–200 cm soil profile and soil temperatures were increased for mulching treatments compared with CK. RFMS utilized soil water efficiently by increasing rainwater harvesting efficiency and transpiration while decreasing soil evaporation. RFMS significantly increased soil temperature in the ridges by 4.0–4.4 °C and reduced diurnal soil temperature amplitude in the furrows, thereby increasing soil thermal time. These positive effects of RFMS compared with CK improved maize growth and crop yields because of adequate absorption and utilization of water and thermal resources. RFMS increased average maize yield by 24.9–32.8%, WUE by 34.1–45.7%, and TUE by 15.9–21.1%. The highest grain yield, WUE, and TUE were observed with WRM due to its favorable soil hydrothermal conditions. The WRM treatment is a promising water-saving and high-yielding maize cultivation practice to improve grain yields and resource use efficiency in dry sub-humid regions.
•Different ridge-furrow and mulching patterns were tested in dry sub-humid regions.•RFMS improved rainwater harvesting efficiency, soil water availability, and ridge soil temperatures.•RFMS reduced diurnal soil temperature amplitude and evapotranspiration in maize growing season.•RFMS significantly increased maize growth, grain yields, WUE, and thermal time use.•The WRM treatment results in highest maize production and resource use efficiency.
Plastic mulching is an important agricultural practice to increase crop yield by increasing soil temperature and moisture. Plastic mulching can also affect soil greenhouse gas emissions e.g., N2O ...emissions and NH3 volatilization and soil characteristics such as soil enzyme and microbial activities, but the simultaneous effects of plastic mulching on these parameters and the potential links between them are rarely evaluated. Here, we conducted a field study to investigate the concurrent responses of N2O emissions, NH3 volatilization, soil enzyme and microbial activities, soil dissolved organic C (DOC) and N (DON), and crop yield to plastic mulching (mulching) and no mulching (ambient) under consecutive winter wheat–summer maize rotation cycles in China’s Loess Plateau. The mulching treatment significantly increased soil water-filled pore spaces (WFPS) and soil temperature during growing cycle 1 (2018–2019 winter wheat and 2019 summer maize) and cycle 2 (2019–2020 winter wheat and 2020 summer maize). Averaged across both growing cycles, the mulching treatment significantly increased winter wheat yield by 31.8 %, summer maize yield by 36.4 %, soil NO3–-N content by 18.2 %, NH4+-N content by 27.4 %, cumulative N2O emissions by 34.0 % and NH3 volatilization by 50.6 %, relative to the ambient treatment. Moreover, the mulching treatment significantly enhanced soil alkaline phosphatase, invertase, catalase, and urease activities and soil microbial biomass C and N contents in the 0–10 cm soil layer across both growing cycles. This study revealed a tradeoff, with plastic mulching significantly improving crop yields and soil enzyme and microbial activities but not mitigating N2O emissions or NH3 volatilization. Our results highlight that simultaneously documenting gaseous N emissions and changes in soil properties under plastic mulching can advance the understanding of sustainable agriculture in semi-arid areas.
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•Soil water-filled pore spaces and soil temperatures differed highly in plastic mulching and no mulching.•Plastic mulching had higher grain yield and soil mineral N content than no mulching.•Plastic mulching significantly improved soil enzyme and microbial activities.•Plastic mulching increased NH3 volatilization and N2O emissions.
•The soil mulching in the sub-humid drought-prone regions can increase WUE and improve crop yield as well as in semi-arid regions.•Soil mulching practices reduce non-productive soil evaporation (E) ...and increase productive plant transpiration (T).•All mulching treatments had significant and positive effects on wheat and maize yield.•The beneficial effects of mulching on soil mainly occurred from sowing to jointing stage of both wheat and maize.•The PSM treatment (plastic film combined with straw mulch) lead to favorable soil water and thermal status.
The application of soil mulching is widely used to improve crop productivity within semi-arid regions of China, but little is known when using a crop rotation system in the sub-humid drought-prone regions as to whether the mulching practice may perform as well as in semi-arid regions. A field study was conducted during two consecutive cycles of a wheat (Triticum aestivum L.) - maize (Zea mays L.) cropping system within the Yangling District of Northwest China to evaluate the effects of different mulch cultivation practices on soil water contents and soil temperatures (EM50 probes), crop yields, and water use efficiency (WUE). Four treatments were evaluated: (1) a flat plot without mulch control treatment (CK), (2) a flat plot with straw mulch (SM), (3) a flat plot with plastic film mulch (PM), and (4) a ridge-furrow planting with film mulch over the ridge and wheat straw mulch over the furrow (PSM).
All mulch treatments significantly improved grain yields and WUE of the winter wheat and summer maize in comparison with CK. The highest grain yields and WUE occurred in the PSM treatment over the two wheat-maize cycles. The average soil water storage within the 0–200 cm soil layer was 3.82%, 2.25%, and 1.31% higher under the PSM, PM, and SM treatments, respectively, in comparison to the CK treatment.Although the soil mulching practices insignificantly changed the total crop evapotranspiration (ET) with a small quantity compared with non-mulched treatment, they tended to reduce non-productive soil evaporation (E) and increase productive plant transpiration (T). All mulching treatments increased the soil temperature of the winter wheat from the seedling to the regreening stages and helped prevent freeze damage. The PSM and SM treatments effectively inhibited the excessive soil temperature rise during the growth stage for summer maize. The PSM treatment resulted in favorable soil moisture and temperature conditions that increased the grain yields and water use efficiency of winter wheat and summer maize. Therefore, we concluded that ridge-furrow planting with film mulch over ridge and wheat straw mulch over the furrow is an effective management practice to increase yields and WUE in a winter wheat-summer maize crop rotation within this sub-humid drought-prone region.
•Ridge with plastic mulch-furrow irrigation method reduced deep percolation amount and soil salt accumulation.•Compared with the conventional border irrigation, ridge with plastic mulch-furrow ...irrigation with acceptable irrigation amount increased irrigation water use efficiency and maize yield.•Ridge with plastic mulch-furrow irrigation with about 300 mm of irrigation water can be recommended as the effective soil and water management practice in the Hetao Irrigation District.
The inadequate soil and water management has resulted in ecological and environmental problems in Hetao Irrigation District, which is characterized by low precipitation, high evaporation and soil salinity issues. A two-year field experiment was conducted to investigate the effects of the combined application of irrigation methods, irrigation amounts and plastic mulching modes on soil moisture, soil salinity, and water use efficiency of spring maize. This experiment included four treatments: (i) border irrigation partially mulched by plastic film with full irrigation amount (CK), (ii) ridge-furrow irrigation not mulched by plastic film with high irrigation amount (NRF), (iii) ridge with plastic mulch-furrow irrigation with high irrigation amount (PRF), (iv) ridge with plastic mulch-furrow irrigation with low irrigation amount (PRL). The results demonstrated that soil water and soil salinity mainly changed in the upper 80 cm soil layer. The proportion of the amount of deep percolation in the total growing season ranged from 9.3% to 29.5% and the highest deep percolation amount appeared in CK. Less irrigation amount generally resulted in a higher salt accumulation in the upper 40 cm soil layer. At harvest, the highest salt accumulation appeared in PRL and the lowest salt accumulation appeared in PRF among the three ridge-furrow irrigation treatments. Compared with the CK treatment, the average grain yields in the PRF, PRL and NRF treatments were increased by 29.6%, 12.2% and 14.4% in 2015, and increased by 5.5%, 4.2% and 2.5% in 2016, respectively. The highest water use efficiency was found in the treatment with PRF in 2015 growing season, and in the treatment with PRL in 2016 growing season. Irrigation water use efficiency was lower in PRF than in PRL, whereas higher than in CK and NRF. Fully considering maize yield, soil water storage, soil salt balance and water use efficiency in the Hetao Irrigation District, ridge with plastic mulch-furrow irrigation with about 300 mm of irrigation water can be recommended as the effective soil and water management practice.
Organic substitution (partial substitution of chemical fertilizer with organic fertilizer) is an effective approach to address soil degradation caused by excessive application of chemical ...fertilizers, particularly in saline areas. This study aimed to evaluate the effects of different organic substitution proportions by using organic fertilizer made from agricultural wastes on saline-sodic soil properties and sunflower (Helianthus annuus L.) growth in an arid saline area. Additionally, the study tried to reveal the possible mechanism of organic substitution on soil quality improvement from soil structure. A two-year field experiment was conducted in the Hetao Irrigation District, northwest China during the sunflower growing season in 2019 and 2020. The study soil type is saline-sodic soil with ECe of 18.3 dS m−1, pH of 8.3, and exchange sodium percentage (ESP) of 18 % in the 0–0.2 m soil layer, with a silt loam soil texture. Based on the recommended total N input (180 kg ha−1) for sunflower, four treatments were designed with three replicates: (i) CK (no fertilization), (ii) OF0 (chemical fertilization only), (iii) OF1 (organic fertilizer substituting 50 % of the urea N), and (iv) OF2 (organic fertilizer substituting 100 % of the urea N). Totally 12 plots were arranged in a randomized complete block design. The results showed that in the 0–0.4 m soil player, compared with OF0, OF1 and OF2 significantly decreased bulk density by 4 % and 6 %, respectively, and turbidity of soil suspension by 36 % and 66 %, respectively. Additionally, OF1 and OF2 significantly increased soil total porosity in 0–0.4 m soil player, mainly in macro-porosity (> 30 µm) and meso-porosity (0.2–30 µm), and increased soil water content compared with OF0 and CK. The improvement of soil structure was attributed to the amelioration of sodicity (reduction of sodium adsorption ratio (SAR) or cation ratio of soil structural stability (CROSS)), and as its consequence, leaching of salt out of the surface layers. Furthermore, compared with OF0 and OF2, OF1 maintained a stable NO3-N supply and significantly increased agronomic efficiency of applied nitrogen by 29 % and 22 %, respectively. Moreover, OF1 on average significantly increased grain yield by 9 % and 8 %, crop water productivity by 12 % and 4 %, and net income by 7 % and 23 %, respectively. Mantel tests revealed that soil water content in the root zone and NO3-N concentration in the maturity stage were key indicators significantly affecting sunflower growth under the organic substitution. In conclusion, from the perspective of improving the soil properties, crop water-fertilizer productivity, and economic benefits, organic fertilizer substituting 50 % of the urea N was recommended for sunflower production under the arid saline environment.
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●Organic substitution reduced suspension turbidity and increased meso-porosity (0.2–30 µm) and macro-porosity (> 30 µm).●Organic substitution increased soil structural stability by decreasing sodicity.●Organic substitution increased soil moisture and decreased soil salinity.●A 50 % organic substitution provided sufficient N supply and increased water-fertilizer productivity.
Straw application has a wide range of environmental benefits that make it an effective practice for sustainable agriculture. However, little is well known about the impacts of ammoniated straw ...addition on soil water and crop canopy characteristics in maize cultivation systems. A 3-year field experiment of summer maize (Zea mays L.) in Northwest China was conducted to evaluate the effects of different straw applications on soil water storage, maize canopy growth, grain yield and water use efficiency (WUE). The three treatments were: (i) no straw (traditional tillage, CK), (ii) straw mulch (traditional straw returning, T1), and (iii) ammoniated straw incorporated into the soil (optimized straw returning, T2). The T2 treatment increased average WUE by 14.8%, 7.8%, and 16.1% in 2016, 2017, and 2018, respectively, relative to the CK treatment. The 3-year average grain yield of the T2 treatment was 13.5% and 8.3% greater than grain yield of the CK and T1 treatments, respectively. Harvest index and 100-kernel weight of summer maize in the T2 treatment were higher than observed for the CK and T1 treatments. Across the three growing years, the T2 treatment was superior over the T1 and CK treatments in improving average LAI, spatial density of leaf area, green canopy cover and aboveground biomass. Hence, our study recommends that using ammoniated straw incorporation could be a promising application for synergistically improving maize growth, WUE and grain yield within this semi-arid region.
•We investigated the effects of straw application on maize morphological traits and grain production.•Ammoniated straw incorporated into the soil improved maize leaf growth and increased aboveground biomass.•Principal component analysis identified the influential values of maize growth under straw incorporation.•Ammoniated straw incorporation could be recommended as a promising straw practice in semi-arid agricultural systems.
Plastic film mulching (PM) has been extensively used to increase crop yields in dryland regions in China. However, the impact of differently colored PM on crop radiation utilization due to the ...optical properties of the underlying PM surfaces remains unclear. We conducted a two-year field experiment in northwest China to evaluate the dynamics of photosynthetically active radiation interception and absorption (fIPAR and fAPAR), as well as the radiation use efficiency for intercepted and absorbed radiation (RUEi and RUEa) during spring maize (Zea mays L.) growth periods. Two fertilization levels (high and low) and 3 PM treatments (transparent film, black film, and no film) were considered in this study. We also developed empirical regression functions to calculate canopy fAPAR, accounting for both canopy and underlying surface characteristics. Furthermore, we used canopy absorption radiation to drive the Soil-Plant-Atmosphere Continuum System (SPACSYS) model to simulate maize biomass and yield. We found that transparent film mulching (TM) exhibited higher fIPAR and fAPAR than black film mulching and no mulching (CK). TM had an increase of RUEi and RUEa by 10.6% and 9.7%, respectively, relative to CK, resulting in a 9.3–19.2% increase in maize yield and a 25.8–30.2% increase in the partial factor productivity of nitrogen. These increases were mainly attributed to the increased relative chlorophyll content, net photosynthesis rate, and extended grain-filling period under TM. We found that the modified radiation input increased the accuracy of the SPACSYS model in simulating maize biomass and yield. We underscore the importance of using TM in dryland areas to increase crop yields and advocate for incorporating canopy radiation data into crop models, especially in agricultural regions where plastic film mulching is used, to enhance the accuracy of yield simulations.
•Transparent film mulching (TM) with high nitrogen produced the highest maize yield.•TM increased light intercept and absorbed fraction (fAPAR).•We established empirical regression functions to calculate canopy fAPAR.•Soil–Plant–Atmosphere Continuum System (SPACSYS) model well simulated yield with modified radiation input data.
•The improved drip irrigation facilitated applied water infiltration and redistributed soil salt.•Salt load was managed below dangerous levels with meager 5-mm drip irrigations.•An SMP of −20 kPa was ...proposed to initiate drip irrigation in the impermeable saline-sodic soil.
A saline-sodic wasteland of takyric solonetz is widely distributed across arid regions of Northwest China. The poor soil structure and low permeability (Ks < 0.1 mm d−1) hinder reclamation because the excessive sodium salt occurring mainly in the surface soil layer cannot be leached down by conventional leaching methods, including drip irrigation, without any assistance measure. The objectives of this study were: 1) to characterize salt movement that occurs within the planted ridge due to drip irrigation of varying amounts, and 2) to identify the optimum soil matric potential (SMP) threshold for drip irrigation in order for wolfberry (Lycium barbarum L.) to be successfully produced, based on plant survival and productivity. A three-year field experiment was conducted with wolfberry using drip irrigation on this solonetz soil. The soil was improved by creating shallow sand-filled niches beneath drip emitters. Five SMP levels triggered irrigations of 5 mm: −5 kPa (S1), −10 kPa (S2), −15 kPa (S3), −20 kPa (S4), and −25 kPa (S5). The improved drip irrigation system significantly facilitated soil water infiltration, and redistributed soil salt in the planted ridge. The leached salt accumulated increasingly at the surface layers of the ridge slope and furrow. Irrigating at higher threshold SMP resulted in lower soil salinity in the root zone. Crop evapotranspiration (ET) was affected by different drip regimes, and lower SMP resulted in reduction in irrigation application amount and ET. Deep percolation was always <8 mm during the three–year study. Soil salinity in the root zone at the end of the study under the S1–S4 treatments decreased to <8.9 dS m−1, the salt-tolerant threshold of wolfberry. At the end of the study, wolfberry survival rate and productivity were greatest for the S2–S4 treatments. These results and the greater water use efficiency found with the S3 and S4 treatments suggest using an SMP threshold of −20 kPa to trigger drip irrigation for wolfberry production on this impermeable saline-sodic soil.
