Ridge-furrow Mulching Research Articles

Characteristics of Soil Respiration and Organic Carbon Mineralization in Dryland Potato Fields Under Different Ridge-furrow Mulching Patterns

Exploring the response mechanism of soil respiration rate to hydrothermal factors and organic carbon mineralization under different ridge-furrow mulching modes is of high importance for the development of the regional carbon cycle and assessment of its ecological benefits. An experimental study was carried out in 2020 in a dry-crop potato field in the mountainous area of southern Ningxia by setting three furrow-ridge ratios [60 cm∶30 cm （R1）, 60 cm∶45 cm （R2）, and 60 cm∶60 cm （R3）] combined with three mulching modes [ridge covered with ordinary plastic film, furrow covered with straw （DJ）, degradable water-permeable plastic film （DS）, and no mulching （DB） in furrows, respectively]. The soil hydrothermal factors, respiration rate, organic carbon content, and mineralization characteristics of potatoes during the reproductive period under different mulching modes were investigated with plain mulching without mulching （CK） as the control. The results showed that different furrow-ridge ratios combined with the mulching mode could significantly increase the soil water storage capacity in the 0-60 cm layer, and the R3DJ treatment had a better effect, with a significant increase of 24.99% compared with that in CK. The R2 treatment had the best effect of increasing temperature during the whole life cycle of the potato. The DS treatment had the effect of increasing temperature, and the DJ treatment had the effect of decreasing temperature under different mulching materials. Different furrow and ridge cover patterns could significantly increase the average soil respiration rate during the reproductive period, and the R3DS treatment was the most significant among the different furrow and ridge cover patterns, with a significant increase of 24.71% compared with that in the CK treatment. The soil organic carbon content in the 0-20 cm and 20-40 cm layers at harvest time was higher in the R2 and R1 ridges, respectively, and higher in the DB and DS treatments for different mulching materials. The soil organic carbon mineralization rate declined rapidly in the early stage of cultivation and then slowly declined and leveled off in the middle and late stages, which was highest in the R3 treatment for the three types of ridge ratios and highest in the DS treatment for different mulching materials. The fitting equations of soil respiration rate with soil hydrothermal factors during the reproductive period revealed that the synergistic effect of soil hydrothermal dual factors on soil respiration was higher than that of a soil hydrothermal single factor and that the quadratic hydrothermal dual factors could well explain 86.4% to 99.9% of the soil respiration. Correlation analysis showed that the average soil respiration rate during the whole life span of the potato was highly significantly and positively correlated with the average soil temperature in the 0-25 cm layer and the average soil organic carbon mineralization rate in the 0-40 cm layer, and the soil temperature was highly significantly and positively correlated with the organic carbon mineralization rate. The furrow-ridge ratio combined with the mulching mode was shown to improve the soil hydrothermal environment and increase the rate of organic carbon mineralization, thus affecting the soil respiration rate, with a furrow-ridge ratio of 60 cm∶45 cm or 60 cm∶60 cm under the ridge mulching mulch ditch covering biodegradable seepage mulch mode being more effective.

Quantitative evaluation of soil water balance under a ridge-furrow rainwater harvesting system in Chinese rainfed agroecosystem.

The ridge-furrow rainwater harvesting system (RFRH) is an advanced farmland management technology that plays a vital role in making full use of rainwater resources. However, it is not clear that RFRH affects crop yield and water use efficiency (WUE) by regulating soil water storage (SWS). Therefore, the present study conducted a meta-analysis to make a large compilation of previous studies and indirectly quantify the impact of RFRH on crop yield and WUE by analysing the effect of RFRH on SWS. The results showed that RFRH improved crop yield and WUE by 26.71% and 25.86%, respectively, by increasing SWS by 3.93% compared to the traditional flat cultivation. RFRH had a significant effect on increasing crop yield and WUE and improving SWS. A low ridge-furrow ratio and ridge-furrow mulching were recommended to obtain positive effects on crop yield and WUE when potatoes are grown in areas with high precipitation (600-800 mm). Furthermore, when nitrogen fertilization is applied during the crop growth period, we also found that a medium nitrogen fertilizer rate is recommended to achieve a significant positive effect on crop yield and WUE. Importantly, a win-win analysis showed the proportions of various groups in the target zone (zone I) to determine the appropriate strategy for RFRH of crops. The present study provides a scientific reference for the future application of the RFRH. The study provides scientific recommendations on crop types, ridge-furrow configurations, plastic mulching patterns and nitrogen fertilizer rate for future RFRH applications. © 2024 Society of Chemical Industry.

Evaluation of N nutrition and optimal fertilizer rate for ridge-furrow mulched maize based on critical N dilution curve under different water conditions

Optimizing nitrogen (N) management based on the critical N dilution curve (NCDC) has been proven a precision fertilization strategy to diagnose crop N nutrition status. However, few explorations have been done to establish a NCDC for dryland maize under double ridge-furrow mulching, a planting system that has been widely adopted in semi-arid areas. Moreover, the influences of various rainfall conditions on NCDC remain unclear. Therefore, a 9-yr field nitrogen fertilization experiment from 2013 to 2021 (five nitrogen rates: 0, 75, 150, 225, and 300 kg N ha–1, respectively, represented by N0, N0.25, N0.50, N0.75, and N1) was applied to established the NCDC under two planting systems (Flatting without mulching, CK; Double ridge-furrow with mulching, DRFM) and two rainfall types (rainfall season and drought season). Compared with CK, DRFM significantly increased plant dry matter (PDM, 5.5–12.8%) and N concentration (4.2–6.9%), ultimately improved grain yield (+16.9%), cumulative nitrogen recovery efficiency (CNRE, +9.8%) and crop water productivity (WPc, +26.3%). Rainfall from jointing to silking stage was an important contributor to grain yield. Compared with rainy season, drought season triggered a 51.7% yield loss and 17.1% reduction in NRE, respectively. The NCDC of the CK and DRFM were Nc=36.6×PDM−0.37 and Nc=38.4×PDM−0.36 in rainy season, respectively; the NCDC of the CK and DRFM were Nc =34.5×PDM−0.27 and Nc=37.3×PDM−0.30 in drought season, respectively. The nitrogen nutrition index (NNI) and plant nitrogen requirement (PNR) based on the NCDC intuitively recorded the N nutritional status. The improved soil micro-environment, PDM and N uptake was recorded in N0.75 (225 kg N ha–1 yr–1) under wet season and in N0.50 (150 kg N ha–1 yr–1) under drought season, respectively, which brought an increase in crop productivity with a suitable N nutrition status. The findings highlight an accurate and effective method for assessing the N nutrition status of rainfed maize, and optimize fertilization strategy for sustainable production in semi-arid regions.

Analysis and Research on Production Effects of Full-Film Double Ridge-Furrow Mulching with Polyethylene Film and Biodegradable Film Based on AquaCrop

Water is an important factor limiting the development of arid rain-fed agriculture. Film mulching is an effective way to ensure yield in arid areas. However, whether biodegradable film can be used instead of polyethylene film for agricultural production in arid areas is a matter of contention. In this study, AquaCrop model simulation and field experiment were used to analyze the production effect of corn whole film double ridge furrow sowing technology covering polyethylene film (PM) and biodegradable film (BM) in Dingxi City from 2016 to 2020. The results showed that the AquaCrop simulation data have a high fitting with the field test data, and the model was suitable for simulating dry farming in Dingxi City. The best sowing time in Dingxi City is to select the average temperature to be stable at about 15 °C (around 15 April to 25 April each year), and the yield is the highest after sowing during this period. Although BM can achieve environmental protection and energy saving, it is weaker than PM in water storage and soil evaporation inhibition in arid areas. The average yield, aboveground biomass, water productivity, and harvest index of PM were 63.95%, 18.57%, 76.35%, and 38.22% higher than those of BM, respectively. In drought years, BM water stress on leaf expansion, induced stomatal closure, and premature senescence were 61%, 17%, and 9.5% higher than PM, respectively, and the stress time was 28.5 d, 5 d, and 26 d, respectively. The maximum canopy coverage and effective root zone water content were 24.5% and 30.49% lower, respectively. In the wet year, water stress under BM only had a certain effect on the leaf expansion of crops but had no effect on the induction of stomatal closure and premature senescence. The maximum canopy coverage and effective root zone water content were 13.56% and 31.35% lower, respectively. The above studies show that BM has a certain ability to store water and preserve moisture, but the parameters of PM are better than BM. Especially in dry years, the crop production efficiency of PM is more significant. It can be seen that in rain-fed agricultural areas with rainfall less than 500 mm, biodegradable film can not replace polyethylene film.

Ridge-furrow mulching combined with appropriate nitrogen rate for enhancing photosynthetic efficiency, yield and water use efficiency of summer maize in a semi-arid region of China

Ridge-furrow mulching combined with appropriate nitrogen rate for enhancing photosynthetic efficiency, yield and water use efficiency of summer maize in a semi-arid region of China

Effects of mulching types on the yield and water utilization by broomcorn millet (Panicum miliaceum): Results of a study in the Loess Plateau, China

Mulching practices have been widely adopted to improve rainfed crop productivity. However, the major resources including water, heat, and light that influenced the yield of broomcorn millet in different dryland regions have rarely been explored. A three-season field experiment with three mulching practices i.e. traditional planting with non-mulching (TP), ridge-furrow mulching system (RF), and plastic film mulching (PFM) was conducted in three semi-arid regions in the Loess Plateau, China, i.e. Guyuan city (GY), Huining county (HN), and Yulin city (YL) between 2020 and 2022 to investigate the impacts of mulching regimes on soil hydrothermal conditions, agronomic characteristics, leaf photosynthetic properties, broomcorn millet yield, and water use efficiency (WUE). Results showed that both PFM and RF treatments increased soil temperature and moisture, and enhanced dry matter accumulation by promoting leaf photosynthetic capacity and chlorophyll content, thereby improving broomcorn millet yield and WUE. PFM and RF increased the average broomcorn millet yield by 15.08% and 24.86% at GY site, 20.86% and 25.61% at HN site, and 15.75% and 25.57% at YL site, respectively, and increased the average WUE by 16.31% and 27.48% at GY site, 23.21% and 28.80% at HN site, 15.55% and 28.57% at YL site, respectively. Partial least squares path modeling analysis revealed that soil moisture was an important environmental factor in determining broomcorn millet yield. Overall, RF practice can be taken to improve the management of agricultural climate factors and maximize yield, thereby promoting the sustainable development of dryland agriculture in the Loess Plateau.

Partitioning evapotranspiration using 18O abundance to understand water use efficiency in maize produced using ridge-furrow mulching system

The ridge-furrow mulching system (RFMS) is an efficient farming strategy that has been used widely for improving crop productivity in dryland agriculture. However, the physical mechanism that allows RFMS and its optimal ridge/furrow ratio to drive the efficient utilization of water in fields are unclear. Thus, we conducted a field research for two years with spring maize based on a long-term field experiment in a semiarid region of Northwestern China to quantify evaporation and transpiration, and their relationship with maize growth, yield and water use efficiency (WUE) under RFMS. Three planting patterns of ridge/furrow ratio were tested: (1) RF40, RFMS with 60 cm wide ridges and 40 cm wide furrows; (2) RF60, RFMS with 60 cm wide ridges and 60 cm wide furrows; (3) FP, traditional flat planting (control). Stable oxygen isotope (18O) analysis was used to partition the evapotranspiration (ET) into evaporation (E) and transpiration (T). The results showed that RFMS significantly increased the soil water content (SWC) in the early and late growing season, but not in the middle period (60–120 days after sowing, DAS) when dry matter accumulated rapidly and the highest transpiration occurred. RFMS significantly decreased the nonproductive evaporation, thereby increased the physiologically significant maize transpiration by 25.0–35.7% during the whole growing season. Therefore, the transpiration fraction of ET (T/ET) was 73% and 70% under RF40 and RF60 during the whole growing season, which were significantly higher than FP. Compared to FP, the maize yield and WUE increased significantly by 55.1% and 52.2% under RF40 and by 49.5% and 47.6% under RF60. We found RFMS drives optimization of ET fractions by increased transpiration but decreased evaporation and then improved WUE of maize, higher ridge/furrow ratio (RF40) create uneven line space and higher mulching area in the field, thus drives optimization of ET components and increased yield and WUE the most. Clarification of this physical mechanism improves our understanding of the optimization of maize production under RFMS, thereby helping to optimize the ridge/furrow ratio in semiarid regions.

Supplemental irrigation and modified plant density improved photosynthesis, grain yield and water productivity of winter wheat under ridge-furrow mulching

In the semi-arid and semi-humid areas, ridge-furrow planting with film mulch on the ridge (R) has been found to significantly enhance crop yields and water productivity, but the interaction effects of supplemental irrigation and plant density on the growth, photosynthesis, grain yield and water productivity (WP) of winter wheat under ridge-furrow mulching are still poorly understood. A two-season experiment (during October 2020 - June 2021 and October 2021 - June 2022) was undertaken on winter wheat in a semi-humid but drought-prone area in northwest China, with two cultivation patterns (R, with ridge width of 40 cm and furrow width of 60 cm; F: traditional flat planting), two supplemental irrigation amounts (I0: rainfed; I60: 60 mm of supplemental irrigation equally applied at the overwintering and regreening stages) and three plant densities (D1:240 × 104 plants ha−1; D2: 360 × 104 plants ha−1; D3: 480 × 104 plants ha−1; with row spacing of 20 cm). The results showed that cultivation pattern, supplemental irrigation and plant density had significant effects on soil water content, leaf area index (LAI), aboveground biomass, relative chlorophyll content (SPAD value), photosynthesis, chlorophyll fluorescence parameters and grain yield of winter wheat. In addition, the interaction effects of cultivation pattern, supplemental irrigation and plant density on SPAD value, fluorescence parameters, grain yield, evapotranspiration and WP were significant. Compared to F and I0, R and I60 significantly increased LAI (4.8 % and 4.6 %), aboveground biomass (9.3 % and 8.1 %), SPAD value (5.0 % and 6.4 %), net photosynthetic rate (19.8 % and 11.7 %), maximal PSII quantum yield (Fv/Fm) (5.2 % and 2.4 %), energy transformation potential activities of PSII (Fv/Fo) (4.1 % and 1.5 %), effective PSII quantum yield (ΦPSII) (12.2 % and 9.5 %), grain yield (10.4 % and 13.5 %) and WP (11.8 % and 7.7 %), while they reduced the relative energy excess at the PSII level. Increasing plant density generally improved LAI, aboveground biomass, but it reduced SPAD value, net photosynthetic rate and fluorescence parameters. Grain yield and WP reached their maximum values at D2 under R and at D3 under F, which was because R had a higher plant number (by 25 %) in each row at D3 compared to F due to the decreased row number resulting from the existence of 40-cm-wide ridge under R. The greatest grain yield (7383.5 kg ha−1 and 8577.4 kg ha−1) and WP (20.03 kg ha−1 mm−1 and 21.77 kg ha−1 mm−1) were obtained under RI60D2 during the two growing seasons. These results suggest that ridge-furrow mulching combined with supplemental irrigation and modified plant density of 360 × 104 plants ha−1 can produce high grain yield and WP for winter wheat in the semi-humid but drought-prone areas of northwest China.

Ridge-Furrow Mulching Enhances Capture and Utilization of Rainfall for Improved Maize Production under Rain-Fed Conditions

The capture and utilization of rainwater by crops under various mulching conditions have great importance in agriculture production systems, especially in dry-prone regions. Understanding the effect of mulching on rainwater use efficiency growth and yield of a crop is very important. For this purpose, field experiments were conducted in 2017 and 2018 to evaluate the potential of ridge-furrow mulching on maize growth and development under rain-fed conditions. The field study compared four treatments, i.e., ridge-furrow without mulch (WM), black plastic mulch (BM), transparent plastic mulch (TM) and grass mulch (GM). The BM treatment consistently increased the soil moisture and temperature, resulting in earlier emergence, as well as increased plant height and plant biomass, compared to the WM treatment. Compared to WM, the two-years mean yield of maize with BM, TM and GM were recorded to be increased by 33.6%, 28.1% and 10.8%, respectively. The BM produced a maximal crop growth rate at 90 days after sowing (DAS) as specified by a greater leaf area index. Transpiration rate and leaf stomatal conductance were significantly higher with BM and TM than with WM, however, the BM treatment showed the highest net photosynthetic rate in both years. Net income for the BM treatment was the highest (USD 1226 ha−1) of all the treatments and USD 335 ha−1 greater than WM. As growth, yield and net income of maize were improved with BM, therefore this treatment was found to be the most effective for maize production in rain-fed conditions. This system is evaluated at a small scale, hence to maximize its effectiveness on a large scale, a simulation design needs to be developed.

Effect of a Ridge-Furrow Mulching System and Limited Supplementary Irrigation on N2O Emission Characteristics and Grain Yield of Winter Wheat (Triticum aestivum L.) Fields under Dryland Conditions

Knowledge of the characteristics of N2O emissions and the influential mechanism is of great significance to mitigate greenhouse gas emissions in semi-arid areas. In the present study, a three-year water-control study was conducted; three simulated rainfall amounts (heavy, normal, and light rainfall = 275, 200, and 125 mm, respectively), two wheat (Triticum aestivum L.) planting modes (RF (ridge–furrow mulching system) and TF (traditional flat planting)) and four supplementary irrigation amounts (150, 75, 37.5, and 0 mm) were set up. The effects of different cultivation methods and irrigation amounts on soil N2O emissions, the soil water content, available nitrogen content, and denitrifying enzyme activity were investigated to clarify the N2O emission mechanism in winter wheat fields (Triticum aestivum L.). The results obtained after three years showed that compared with TF, the N2O emissions under RF decreased by 21.62–30.72% (p < 0.001), whereas the soil water content increased by 6.26–8.82%, the available nitrogen content decreased by 1.71–16.24%, and the denitrifying enzyme activities increased by 0.2–24.16% under heavy rainfall conditions. Under conditions with normal and light rainfall, the N2O emission fluxes under RF increased by 3.66–12.46% and 6.08–15.57% (p > 0.05), while the soil water contents increased by 6.13–11.49% and 8.05–13.88%, the soil available nitrogen contents decreased by 11.0–21.42% and 19.93–34.44%, and the denitrifying enzyme activities increased by 0.01–24.08% and 0.03–20.79% compared with TF. Principal component analysis showed that the main factors related to N2O emissions under RF were the soil moisture content and available nitrogen content; these factors combined explained 94.37% the variation of the N2O emissions. However, the main factors under TF were the soil moisture content and denitrifying enzyme activity; these factors combined explained 85.81%. In the heavy and normal rainfall years, compared with TF, using RF and 75 mm irrigation achieved the goal of reducing water usage as well as decreasing the N2O emissions (or N2O increase was not significant). In light rainfall years, RF with 150 mm irrigation obtained significant reductions in water usage compared with TF but it also increased the N2O emission flux. Under different rainfall years, the yield of RF increased by 2.89–50.44% compared with the TF system, and the increase in wheat grain yield increased with decreasing rainfall.

Effects of different ridge-furrow mulching systems on yield and water use efficiency of summer maize in the Loess Plateau of China

Effects of different ridge-furrow mulching systems on yield and water use efficiency of summer maize in the Loess Plateau of China

Wheat straw mulching with nitrification inhibitor application improves grain yield and economic benefit while mitigating gaseous emissions from a dryland maize field in northwest China

• Mulching method and nitrogen type effects on maize yield and gaseous emissions were explored. • No differences in yield and NUE existed between ridge-furrow mulching and straw mulching. • GWP and GHGI increased under ridge-furrow mulching, but decreased under straw mulching. • Urea + NBPT minimized NH 3 volatilization, while Urea + DMPP mitigated N 2 O emission. • Straw mulching with Urea + DMPP was recommended for sustainable dryland maize production. Understanding the comprehensive impact of soil mulching and nitrogen (N) fertilization on agronomy, economy and environment is important for developing sustainable dryland agriculture. A two-year experiment was conducted on dryland maize ( Zea mays L.) in a sub-humid but drought-prone climate zone to explore the responses of grain yield, N use efficiency (NUE), economic benefit, ammonia (NH 3 ) volatilization and greenhouse gas emissions to various mulching methods (NM: non-mulching, SM: wheat ( Triticum aestivum L.) straw mulching and RF: ridge-furrow cultivation with plastic film mulching on the ridge) and N types (U: urea, U + CRU: mixture of urea and controlled-release urea at a ratio of 3:7, U + DMPP: urea with 2 % 3, 4-dimethylpyrazole phosphate and U + NBPT: urea with 2 % N -( n -butyl) thiophosphoric triamide). The results showed that RF and SM significantly increased grain yield and NUE, and decreased residual soil mineral N in the 0−200 cm soil layer relative to NM, but the differences in these indices were not significant between RF and SM. The net benefit under SM was comparable to that under RF (1558.5 and 1613.6 USD ha −1 ). The RF treatment significantly increased global warming potential (GWP) and greenhouse gas intensity (GHGI) by 33.7 % and 20.4 % compared with NM, and by 71.9 % and 67.5 % compared with SM. Compared with urea, U + CRU, U + DMPP and U + NBPT exhibited promoting effect on grain yield and NUE, but decreased residual soil mineral N. Compared with U, U + NBPT and U + DMPP produced much lower NH 3 volatilization and nitrous oxide (N 2 O) emission, respectively. Compared with U, U + CRU also reduced NH 3 volatilization and N 2 O emission, but its economic benefit was 4.9 % lower. Both U + DMPP and U + NBPT exhibited inhibitory effect on methane (CH 4 ) oxidation, but the CH 4 pattern under U + CRU was inconsistent in the two years. The smallest GWP and GHGI were generally observed under U + DMPP among various N types. The interaction of mulching method and N type had significant influence on grain yield in 2019, CO 2 emission in 2018, N 2 O emission, GWP and GHGI in both years. In conclusion, wheat straw mulching with nitrification inhibitor application achieved better balance among agronomic, economic and environmental benefits for dryland maize in northwest China.

Density-dependent maize (Zea mays L.) yield increase in trade-off in reproductive allocation and water use under ridge-furrow plastic-mulching

• Maize yield responses to increasing planting densities were studied in RFM system. • Individual yield declined while population one increased first and then decreased. • This difference resulted from improved soil water availability as affected by RFM. • Optimal density had better trade-off between reproductive and vegetative growth. • Allometric R–V relationship explained density-dependent yield formation under RFM. The law of constant final yield and allometric theory have been seldom used to explore density-dependent yield formation and water use in rainfed farming systems, particularly in ridge-furrow mulching (RFM) system of maize. A two-year RFM field experiment was conducted using maize variety Yuyuan7879 in semiarid Kenya from 2015 to 2016, with four planting densities: 5.2 × 10 4 (D52, conventional density), 6.0 × 10 4 (D60), 6.9 × 10 4 (D69) and 8.5 × 10 4 (D85) plants per hectare. The grain yield and aboveground biomass per plant were significantly decreased with increasing density across two growing seasons. However, the population grain yield significantly was increased from D52 to D60 (from 3395.1–4471.7 kg ha −1 ) but declined significantly from D60 to D69 and D85 (p < 0.05) in 2015 and 2016, respectively. Meanwhile, the population aboveground biomass was significantly promoted from D52 to D60 (p < 0.05) and then remained relatively stable in D69 and D85, achieving a state of constant final yield. Under the improved soil storage, the RFM system raised the rational planting density from conventional D52 to D60 with regard to population yield. Water use efficiency for population yield (WUE G ) was the highest at D52 and D60, followed by D69, and the lowest at D85. However, the WUE for the aboveground biomass (WUE A ) was significantly lower in D52 than D60 and D85. Principal component analysis suggested that the population grain yield and WUE G were significantly positively associated with the reproductive allocation and leaf growth. This result was further affirmed by the allometric relationship between leaf biomass and body size, since the allometric exponent (<1) was raised with density. Allometric relationship between reproductive and vegetative mass demonstrated that the D60 treatment achieved a relatively balanced allocation of photosynthetic products into reproductive organs in comparison with other treatments. The RFM application significantly improved the availability of soil water, and the rational planting density of maize for better yield and WUE G . Thus, this phenomenon mechanically resulted from relatively better trade-offs between reproductive and vegetative growth, together with moderately increased leaf growth.

Can ridge-furrow with film and straw mulching improve wheat-maize system productivity and maintain soil fertility on the Loess Plateau of China?

Ridge-furrow mulching patterns are beneficial to improve crop yields and rainwater use efficiency, but it is not clear whether they can improve productivity and simultaneously maintain soil fertility on the Loess Plateau of China. A three-year (2013–2016) field trial was conducted during the rotation of wheat (Triticum aestivum L.) – maize (Zea mays L.) to investigate the effects of ridge-furrow mulching patterns on soil moisture, soil fertility, grain yield, and water use efficiency (WUE). Four ridge-furrow planting patterns included: (1) white plastic film mulch over the ridge (RW), (2) straw mulch over the furrow (RS), (3) white plastic film mulch over the ridge and straw mulch over the furrow (RWS), and (4) black plastic film mulch over the ridge and straw mulch over the furrow (RBS). Flat planting without mulch was CK. The results showed that RW, RS, RWS, and RBS significantly improved soil water storage and aboveground biomass throughout each winter wheat and summer maize growing season compared with CK. Finally, winter wheat grain yield and WUE in the four mulching treatments markedly increased by 13.0–32.9% and 22.5–41.5% in a wet and cool season, 15.5–35.2% and 19.3–41.9% in a season with normal rainfall and temperatures, and 27.2–58.9% and 15.3–33.4% in a dry and warm season, respectively. Maize grain yield and WUE increased by 12.8–35.0% and 19.5–46.2% in a season with normal rainfall and temperature, 15.0–38.5% and 18.0–39.9% in a dry and cool season, and 17.4–50.5% and 13.0–42.5% in a dry and warm season, respectively. Among the four mulching treatments, RWS and RBS significantly improved the yield and WUE of wheat and maize relative to RW and RS over the three years. After three years, soil total nitrogen content in RWS and RBS was significantly greater than in RS. Besides, soil microbial biomass carbon and nitrogen, and soil dissolved organic carbon and nitrogen contents in RWS and RBS were all markedly higher than in RW and RS. Our results indicated that RWS and RBS were a promising agricultural practice that improved crop production and simultaneously maintained soil fertility in a rain-fed semi-arid region of China.

Water productivity and its allometric mechanism in mulching cultivated maize (Zea mays L.) in semiarid Kenya

Allometry is extensively used to describe the scaling relationship between individual size and metabolite allocation. Micro-field rain-harvesting system can improve soil water availability and thus alter the allocation of individual biomass among organs. Yet the eco-physiological mechanism based on allometric scaling theory has been little investigated under various mulching conditions. A field experiment was conducted using maize variety Yuyuan7879 in Juja, Kenya for two growing seasons (cross-year) from 2015 to 2016, and from 2016 to 2017 respectively. Four treatments were designed as ridge-furrow mulching (RFM) with black plastic mulching (RFMB), transparent plastic mulching (RFMT), grass straw mulching (RFMG) and conventional flat planting (CK). We found that RFMB, RFMT and RFMG significantly increased grain yield by 106%, 109% and 32% in 2015, and 101%, 96% and 30% in 2016 respectively, in comparison with CK. Mulching treatments improved soil temperature and moisture and significantly increased crop water productivity (CWP). Mulching treatments drastically changed the allometric relationship between metabolic rate (leaf biomass) and individual size (lgy = αlgx + lgβ), and optimized the size-dependent reproductive allocation. In the relationship between leaf biomass (y-axis) vs aboveground biomass (x-axis), mulching treatments significantly declined the value of α (α < 1; P < 0.01), suggesting that less photosynthetic product was allocated in leaves in mulching treatments than in CK. As for the allometric relationship between grain yield and aboveground biomass, the α was generally significantly more than 1 in RFMB and RFMT, and significantly less than 1 in RFMG and CK, demonstrating that more photosynthates were allocated to reproductive growth under plastic mulching. Also, the variation of allometric relationship between reproductive and vegetative biomass provided further evidence that plastic mulching facilitated substance transportation from vegetative to reproductive organs. In conclusion, plastic mulching significantly improved soil hydrothermal condition, increased individual reproductive allocation and ultimately improved grain yield and CWP at population level.

Response of productivity and nitrogen efficiency to plastic-film mulching patterns for maize in sub-humid northeast China

In the semi-humid region of northeast China, the plastic-film mulching (PFM) is essential for sustaining yields, while the yield-increase potential and nitrogen (N) use mechanism under different PFM patterns in this area remain poorly understood. A field experiment using maize (Zea mays L.) was conducted for two consecutive years to study the effects of different PFM patterns on soil microclimate factors, N mineralization, N loss, crop yields and N use efficiency under drip irrigation. The six treatments consisted of full ridge-furrow mulching (FM), only ridge mulching (RM), non-mulching (NM), ridge-furrow mulching without fertilization (CFM), ridge mulching without fertilization (CRM), and non-mulching without fertilization (CNM). The results showed that the PFM could obviously warm the soil throughout the growing season. Compared to NM, FM and RM obviously increased the soil temperature by 2.0–5.4 ℃ and 1.6–4.8 ℃ in the 2017 season, respectively, and by 1.9–7.8 ℃ and 1.0–5.7 ℃ in the 2018 season, respectively. Across two years, soil temperature was highest for FM followed by RM and NM. In general, FM enhanced the soil water content compared with RM, especially in the 0–50 cm profile throughout the growing season. The PFM could significantly (p < 0.05) promote soil N mineralization (Nmin). Furthermore, irrespective of fertilization, the PFM significantly (p < 0.05) improved plant N uptake (Nuptake), grain N accumulation (Ngrain) and N harvest index (NHI). Averaged across years, full ridge-furrow mulching and only ridge mulching distinctly enhanced the NHI under fertilization by 6.8% and 6.1%, respectively, relative to non-mulching. Finally, PFM imposed significant influence (p < 0.05) on ear barren tip, 100-seed weight and grain yield. Grain yield under FM and RM were significantly promoted by 15.0% and 12.5%, respectively, compared with NM. Meanwhile, full ridge-furrow mulching could obviously increase grain yield compared to ridge mulching. In conclusion, full ridge-furrow mulching provided a more feasible water-heat environment for soil N mineralization, improving plant N uptake and reducing N loss, and thereby significantly increasing crop productivity and nitrogen use efficiency.

Alternating wide ridges and narrow furrows with film mulching improves soil hydrothermal conditions and maize water use efficiency in dry sub-humid regions

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.

Fully biodegradable film to boost rainfed maize (Zea mays L.) production in semiarid Kenya: An environmentally friendly perspective

Abstract Conventional polyethylene plastic film mulching has been widely used, but its subsequent plastic residue pollution received widespread concern. Fully biodegradable film mulching is viewed as a potential substitution solution, however, it is generally thought not to be efficient as conventional plastic film mulching in field productivity and economic harvest. A two-year field experiment using a newly produced fully biodegradable film was conducted in semiarid Kenya in 2016 and 2017 respectively. Five treatments were designed as: 1) ridge-furrow mulching (RFM) with transparent plastic film (RFMT), 2) RFM with fully biodegradable film (RFMD), 3) RFM with black plastic film (RFMB), 4) RFM with grass straw (RFMG) and 5) traditional flat planting without mulching (FP) as CK. We found that RFMD achieved the similar evaporation-restricted, yield-increased and water-saving effectiveness as RFMT and RFMB did across two growing seasons. The RFMD lowered evaporation by 58.1 mm, while increasing grain yield by 70.16 %, above-ground biomass by 77.7 % and water use efficiency (in reference to grain yield) (WUEG) by 131.8 % in comparison with CK respectively. Furthermore, RFMD increased net economic income by 49.8 % in 2016 and 42.0 % in 2017 respectively relative to CK, as RFMT and RFMB did. It is noted that the degradable film used in this experiment is a non-polyethylene material and still can be maintained for 60 days in a fine physical state. Also, average soil temperature was significantly elevated by 1.6 °C in 2016 and 1.8 °C in 2017 in RFMD respectively, in comparison with CK, which was beneficial to crop growth and grain filling particularly in relatively cool long rainy season. Considering residual film pollution, the biodegradable film showed reliable advantages in environmental friendliness and field productivity. Therefore, it might be a promising farming solution to boost rainfed maize production and environmental sustainability in east African Plateau.

Effects of ridge-furrow mulching system with supplementary irrigation on soil respiration in winter wheat fields under different rainfall conditions

Developing an ecologically friendly supplementary irrigation method is vitally important for improving wheat productivity in terms of reduced water usage and high yields in semiarid areas. In this study, we explored the effects of the ridge-furrow mulching system (RF) with supplementary irrigation on soil respiration in winter wheat fields under different rainfall conditions. Three rainfall conditions were simulated (heavy rainfall =275 mm, normal rainfall =200 mm, and light rainfall =125 mm) and four irrigation treatments (150, 75, 37.5, and 0 mm) were examined during the growth period for winter wheat. A traditional flat (TF) planting was used as the control. The results obtained after three years (October 2015 to June 2018) showed that there was no significant difference in the soil respiration rate between RF and TF under 200 mm and 275 mm rainfall in the winter wheat growth period. Under rainfall at 125 mm, the respiration rate using RF with the same irrigation was significantly increased by 5.31–23.38% compared with that using TF, where the differences among treatments were significant, except for that with irrigation at 150 mm. Under rainfall at 275, 200, and 125 mm, the coefficients of determination for the effects of the soil temperature and water content on soil respiration were lower with RF than TF. The coefficients of determination also tended to increase as the amounts of rainfall and supplementary irrigation decreased. Therefore, to reduce the impact of supplementary irrigation under climate warming, we conclude that the P1R75, P2R150 and P3R150 treatments are suitable ecologically friendly supplementary irrigation method for reducing water usage in semiarid areas.

Ridge-furrow mulching system and supplementary irrigation can reduce the greenhouse gas emission intensity

In this study, in order to explore the greenhouse gas emissions and global warming potential (GWP) in winter wheat fields under the ridge-furrow mulching system (RF) with supplementary irrigation, three rainfall conditions (heavy rainfall = 275 mm, normal rainfall = 200 mm, and light rainfall = 125 mm) and four irrigation treatments (150, 75, 37.5, and 0 mm) were simulated during the growth period. Traditional flat planting (TF) was used as the control and we determined the emissions of N2O, CO2, and CH4, as well as the GWP and greenhouse gas emission intensity (GHGI). The results obtained after three years (October 2016 to June 2019) showed that when the amount of irrigation was the same during the winter wheat growth period, the N2O emission flux, CO2 emission flux, and GHGI under RF decreased by 3.30–23.78%, 5.93–6.45%, and 5.01–23.72% with rainfall at 275 mm, respectively, compared with those under TF. Under the same level of supplementary irrigation, the N2O emission flux, CO2 emission flux, and GHGI decreased by 0.8–4.18%, 5.05–13.53%, and 7.83–13.72%, respectively, with rainfall at 200 mm, and they decreased by 17.49–32.46%, 25.57–35.35%, and 6.22–30.20% with rainfall at 125 mm. Under the three rainfall conditions, the absorption of CH4 in the winter wheat field increased as the supplementary irrigation decreased. Our results showed that the RF system can satisfy the goal of achieving high yields and saving water, as well as reducing the GHGI to contribute less to global climate warming as an environmentally friendly irrigation method.