Flats Plant Research Articles

Black plastic film combined with straw mulching delays senescence and increases summer maize yield in northwest China

Ridge-furrow farming systems with transparent plastic film have been used extensively for maize (Zea mays L.) production in semi-arid areas. However, with climate warming, problems may arise associated with premature senescence and reduced production. This study examined whether dual mulching of ridges with black plastic film and furrows with straw can delay senescence and increase summer maize yield. Summer maize cultivation experiments were conducted in 2014–2015 by ridge-furrow planting with black (BRM) or transparent (TRM) plastic film mulch over the ridge and wheat straw mulch over the furrow, flat planting with black (BM) or transparent plastic film mulch (TM), and flat planting without mulch (control treatment, CK). The objective of this experiment was to determine the effects of the different mulching treatments on soil water and temperature, evapotranspiration (ET), leaf, photosynthesis rate, yield, and water use efficiency of summer maize. The BRM and TRM treatments were superior to the BM and TM treatments in terms of soil water storage in the 0–200 cm soil profile. The BRM reduced the diurnal variation in the soil temperature and lowered the soil temperature in the root zone. The BRM treatment extended the maize reproductive growth period by 5 days compared with TM, and 2–3 days longer than for the other mulched and control treatments. The BRM also increased the leaf area and dry matter accumulation per plant while significantly increasing the leaf photosynthesis rate. Moreover, BRM increased the 100–seed dry weight and significantly improved yield and water-use efficiency. The 2–year average yield of the BRM treatment was 6.7, 13.4, 18.4, and 72.9 % greater than yield of the TRM, BM, TM, and CK treatments, respectively. The corresponding water-use efficiency improved by 11.2, 13.1, 20.3, and 72.1 %, respectively. Applying the BRM cultivation practice will effectively delay senescence and increase summer maize yield in the agricultural production area of the study region.

The role of ridge‐furrow with plastic film mulching system on stem lodging resistance of winter wheat in a dry semi‐humid region

AbstractRidge‐furrow with plastic film mulching (RFPFM) is widely used as a water‐saving strategy for the improvement of crop yield. However, lodging susceptibility under RFPFM practices has not yet been determined. A 2‐yr field study comprising of three cultivation strategies (rain‐fed flat planting [FP], RFPFM, and well‐water planting [WW]) and two N application rates (75 and 225 kg N ha–1) was conducted to assess the risk of lodging and the relationship between lodging resistance and grain yields of two wheat (Triticum aestivum L.) varieties (Xinong979 as lodging resistant and Xiaoyan22 as lodging susceptible). The results showed that higher N application increased lodging index under FP and RFPFM, and the lodging index was 33% lower under RFPFM than under WW. In both years, there was a positive relationship between grain yield and lodging susceptibility (R2 = 0.62** and 0.57**) implying that promoting crop yield by using RFPFM strategy accelerates the risk of lodging. When compared with WW, RFPFM significantly reduced the lodging index, while sustaining a comparable grain yield. Overall, RFPFM could be highly recommended as a promising strategy for winter wheat producers in dry, semi‐humid regions. The close relationships of breaking resistance and lodging index with both mass density and stem wall thickness of basal internode suggest that selection for increased stem strength trait could lead to improved lodging resistance and higher yields in future programs for winter wheat cultivar improvement.

Raised seedbeds and irrigation increase the yield of soybean rotated with rice in lowland of Southern Brazil

Abstract: The objective of this work was to evaluate the effect of raised seedbeds associated with irrigation on the yield of soybean (Glycine max) rotated with rice (Oryza sativa) in lowland conditions in Southern Brazil. Field experiments were conducted in two crop seasons (2014/2015 and 2015/2016), with two planting systems (raised seedbed and flat planting) and two irrigation managements (irrigated and nonirrigated). Water use, biological nitrogen fixation, and yield were evaluated. The water used for raised seedbeds was 14% (151 m3 ha-1) and 27% (163 m3 ha-1) lower than that for flat planting in the first and second crop seasons, respectively. Irrigation increased nodule number per plant, nodule dry weight, and biological nitrogen fixation. The average grain yield of the raised seedbed system was 10% (529 kg ha-1) and 9% (362 kg ha-1) higher than that of flat planting in 2014/2015 and 2015/2016, respectively. Irrigation improved yield by 5% (203 kg ha-1) and 7% (265 kg ha-1) in each crop year. The use of raised seedbeds associated with irrigation improves the yield of soybean grown in rotation with rice in lowland in Southern Brazil.

Incorporation of Manure into Ridge and Furrow Planting System Boosts Yields of Maize by Optimizing Soil Moisture and Improving Photosynthesis

A sustainable management strategy of soil fertility and cropping system is critical to guaranteeing food security. However, little is known about the effects of soil amendment strategies on crop growth via regulating soil moisture and photosynthesis in a ridge and furrow cropping system. Here, field experiments were carried out in 2017 and 2018 in semi-arid areas of Loess Plateau, northwest China to investigate the effects of integrated use of ridge and furrow planting and manure amendment on grain yields of maize. Four treatments were designed: CK (flat planting with 100% chemical fertilizer), RFC (ridge and furrow planting with 100% chemical fertilizer), RFR (ridge and furrow planting with 100% control-released fertilizer), and RFM (ridge and furrow planting with 50% manure fertilizer + 50% N fertilizer). On average, RFM increased photosynthetic rates (Pn) by 74%, followed by RFR by 47%, and RFC by 26%, compared to CK. Also, stomatal conductance (Cd), transpiration rates (Tr), and intercellular CO2 concentration (Ci) were highest with RFM, followed by RFR and RFC. Averaged across the two years, RFM conserved 10% more soil water storage (SWS) than CK did at harvest, followed by RFR with an increment by 8%. However, RFC consumed more soil water than CK did, with its ETc 8% higher than CK. Consequently, spring maize treated with RFM suffered less drought stress, especially in 2017 when precipitation was insufficient. On average, grain yields and water use efficiency of RFM were increased by 18% and 27%, compared to CK. Structural equation modeling analysis showed that there existed significant positive correlation between SWS in top layers and grain yields, while SWS in deep layers had negative effects on grain yields. In conclusion, the incorporation of manure into ridge and furrow planting system can be an efficient agronomic practice to improve plant photosynthesis, optimize soil moisture, and boost grain yields in semi-arid areas of Loess Plateau, northwest China.

Optimizing fertilization under ridge-furrow rainfall harvesting system to improve foxtail millet yield and water use in a semiarid region, China

Effects on the soil water and foxtail millet yield of different fertilizer rates coupled with the ridge-furrow rainfall harvesting system (RFRHS) are unclear, which could guide improvements to productivity in dryland farming. We conducted field experiments using RFRHS and traditional flat planting (TFP) at four different fertilizer rates: (i) no fertilizer (CK); (ii) low (L), N 90+P2O5 60 kg ha–1; (iii) medium (M), N 180+P2O5 120 kg ha–1; and (iv) high (H), N 270+P2O5 180 kg ha–1. RFRHS significantly improved the topsoil water content (by 4.7–8.5% in 0–40 cm layer) and topsoil temperature (by 0.4–0.7 °C), which stimulated stable seedling establishment and accelerated millet growth. Fertilization significantly enhanced water absorption in 0–140 cm profile, prolonged the growth period of millet and significantly increased dry matter accumulation. Finally, under RFRHS, the grain yield and water use efficiency (WUE) of foxtail millet increased by 6.2% and 6.7%, respectively, compared with TFP, and they tended to increase more as fertilizer rate increases, indicating a positive interaction between water and nutrients. However, under RFRHS, the M fertilizer rate obtained a higher yield (average 6748.6 kg ha–1), WUE (average 18.6 kg ha–1 mm–1) compared with CK and L rates, and made a greater contribution to the grain yield (average 32.1%), but no further significant increases were observed with the H fertilizer rate where RFRFS showed a tendency to decrease grain yield compared to TFP in wet years. Therefore, RFRHS with fertilizer application at a rate of N 180+P2O5 120 kg ha–1 may be suitable for high-efficiency farming management to improve the yield and WUE for foxtail millet in this semiarid region.

Supplemental irrigation strategy for improving grain filling, economic return, and production in winter wheat under the ridge and furrow rainwater harvesting system

The plastic-covered ridge and furrow rainwater harvesting (RFRH) system has been used widely to enhance crop productivity in the semiarid regions of China. We conducted a field study during 2015–2017 where the RFRH method was combined with deficit irrigation to decrease the irrigation water usage and improve the crop water productivity (CWP) and irrigation water productivity (IWP). Under the RFRH system, the amount of irrigation was reduced by half compared with that under traditional flat planting (TF) with border irrigation due to the effects of precipitation harvesting. Half of the deficit irrigation was supplied before wintering and the remaining half at the jointing stage. The following eight treatments were tested: RFRH system with 75 mm deficit irrigation (R75), 37 mm irrigation (R37), 18 mm irrigation (R18), and 0 mm irrigation (R0); TF cultivation with 150 mm irrigation (F150), 75 mm irrigation (F75), 37 mm irrigation (F37), and 0 mm irrigation (F0). The results showed that the irrigation volume doubled under conventional border irrigation but the soil water storage was greater under RFRH with deficit irrigation. The R75 treatment resulted in significantly greater soil water storage, reduced evapotranspiration (44.2%), and a higher grain yield (14.6%), thereby increasing CWP (64.8%), ICWP (irrigation crop water productivity) (44.2%), and IWP (57.0%) compared with F150. R75 improved the biomass per plant, leaf area index, and net income for farmers (by 17.5%) compared with F150. Thus, we recommend R75 for decreasing the irrigation water usage and increasing the effective consumption of precipitation in semiarid regions.

Impact of cultivation on soil organic carbon and carbon sequestration potential in semiarid regions of China

AbstractDynamic changes in soil organic carbon (SOC) have become a popular topic in global research on organic carbon as part of the increasing attention being paid to food security and reducing greenhouse gas emissions. In this paper, the semiarid regions of China were selected as a research focus, and SOC data from 1980 to 2015 were analysed using IBM SPSS Statistics 20.0 software. SOC in farmland varied according to cultivated land type, mulching material type and planting method in the studied regions. The SOC content is 10.3–10.8 g kg−1 in supplementally irrigated land and flat dry land, 7.1–8.7 g kg−1 in terraced dry land and river beach land, and 6.2–6.4 g kg−1 in sloping dry land. The SOC content increased to 16.1–17.4 g kg−1 when crop stalks were used as mulch. The increase was only 11.5–13.5 g kg−1 in soils mulched with film or sandstone. The SOC value in wheat, maize and potatoes sown on single or double ridges was 2.4%–3.2%, 35.7%–36.4% and 4.4%–4.8%, respectively, which are higher than the values for wheat, maize and potatoes sown using the flat planting method. The SOC sequestering potential also varied according to the previously noted factors and was improved from 224.1% to 383.8% depending on cultivated land type, from 96.5% to 182.3% depending on mulching material type and from 96.1% to 191.3% depending on planting method. The SOC sequestering potential can be improved by 453.2%–757.4% with the integration of the optimal cultivated land type, mulching material type and planting method. Thus, there is substantial soil carbon sequestration potential in China's semiarid regions.

The effect of tillage on nitrogen use efficiency in maize (Zea mays L.) in a ridge–furrow plastic film mulch system

The widely adopted maize planting pattern of ridge–furrow plastic film mulch (RFPM) in rainfed agricultural areas of the Loess Plateau has resulted in water-saving and increased yields. However, tillage practices used before RFPM may have had varying effects on the spatiotemporal dynamics of surface fertilizers and soil nutrients. To date, no studies have investigated the combined effects of tillage type and RFPM on crop performance. A two-year trial incorporated three treatments—conventional flat planting (CK), rotary tillage before RFPM (MR), and plow tillage before RFPM (MP). Within each treatment plot, a micro-plot was established to trace the fate of urea-N (only 15N labeled in 2017 and 2018). This study aimed to explore the effects of two tillage practices before RFPM on urea-N recovery by crops, crop growth, and water use efficiency.The RFPM significantly improved soil hydrothermal conditions during maize growth—the ridges had lower surface soil moisture contents than the furrows, with more moisture accumulation in the furrows—but water use efficiency did not differ between MR and MP. The spatial distribution of nutrients under RFPM differed between the two tillage practices. The ridges under RFPM had significantly higher soil organic matter (SOM) and total nitrogen (TN) than the furrows, more so in the MP furrows than the MR furrows. Soil NO3−-N did not significantly differ between ridges and furrows, but MP improved nitrogen use efficiency and significantly reduced N2O emissions, relative to MR. At harvest, MP had significantly higher yields than MR and CK, and the highest net income of the three treatments. In conclusion, plow tillage before RFPM had better economic and ecological benefits than rotary tillage and has the potential to help establish sustainable agricultural systems in dryland China.

Comparing Yield, Quality, Water Use Efficiency, and Value between Fodder and Grain Produced Using Ridge‐Furrow Rainwater Harvesting in a Semiarid Region

Agriculture production in study areas benefits from the use of ridge‐furrow rainwater harvesting (RFRH) to supplement rainfall in the absence of irrigation from imported sources. However, it is necessary to select suitable fodder plants for use with RFRH in this climate. In this paper, 10 treatments (3 ridge widths × 3 ridge‐mulching materials + flat planting [FP] as control) in a complete random design were applied in a 3‐yr field experiment for alfalfa (Medicago sativa L.) and oat (Avena sativa L.) production, respectively. Ridges mulched with plastic film (PF) and ridges mulched with biodegradable film (BF) had positive effects on fodder, grain yields, and water use efficiency (WUE), but ridges with manually compacted soil (MCS) had a negative effect on yield and WUE in the most cases. Fodder, grain yields, and WUE decreased as ridge width increased. For oats, the decrease of WUE of MCS was 1.31 kg ha−1 mm−1, but the increase of WUE of BF and PF was 0.83 and 1.25 kg ha−1 mm−1, respectively, compared with that of FP over 3 yr. For alfalfa, the increase of WUE of MCS, BF, and PF was, respectively, 0.22, 5.62, and 6.33 kg ha−1 mm−1. The RFRH systems, especially PF and BF, produced oat and alfalfa fodders with increased crude protein content and decreased acid and neutral detergent fiber content. The average alfalfa fodder yield was 1.37 times greater than that of oats, whereas the average WUE of alfalfa was 2.62 times greater than that of oats. Alfalfa fodder contained higher crude proteins and lower neutral detergent fiber content than oat fodder and had similar acid detergent fiber. It is more economic to harvest oat fodder than to harvest oat grain, and it is more economic to produce alfalfa than to produce oats.

Nutrient and planting modes strategies improves water use efficiency, grain-filling and hormonal changes of maize in semi-arid regions of China

A nutrient in combination of planting modes strategies has not been implemented on grain filling process, hormonal changes in seeds, water use efficiency (WUE) and maize yield. Field study was conducted during 2016–2017 to evaluate the performance to three cultivation techniques, (RF: ridge furrow precipitation harvesting technique with plastic mulching; PM: flat planting with plastic mulching; CP: flat planting without plastic mulching); with four nitrogen levels, (0: 0 kg N ha−1; 1: 100 kg N ha−1; 2: 200 kg N ha−1; 3: 300 kg N ha−1) in semi-arid areas. The results indicated that grain-filling rate, hormonal changes, dry matter per plant, yield components, WUE and ET of maize under the RF technique were significantly higher as compared with PM and CP cultivation techniques under different nutrient management strategies. Under the same cultivation techniques, as N amount increased up to 200 kg ha−1, the soil water storage, phytohormones such as IAA, Z+ZR, ABA content, were significantly improved and reducing GAs, Ethylene evolution rate, which led to improve maize production as compared with control plots. Nitrogen applications at 300 kg ha−1 have significantly reduced soil water storage and ET rate at different cultivation techniques. These results indicated that under the RF3 treatment improved grain filling process, WUE (55.5%) and grain yield (3.0 t ha−1). Nitrogen applications at the rate of 300 kg ha−1 with either RF or PM cultivation techniques significantly affected hormonal changes, therefore, regulating the Wmax, Gmax, Gmean, Tmax, and activity grain-filling period (AGP) of maize. It is concluded from our results that the RF3 treatment is an innovative cultivation technique to significantly improve the soil water storage, WUE, total dry mater accumulation (19.8%); grain filling rates thereby balance hormonal changes in maize seeds, as a result increase maize yields in semi-arid regions.

Effects of deficit irrigation combined with rainwater harvesting planting system on the water use efficiency and maize (Zea mays L.) yield in a semiarid area

The ridge and furrow rainfall harvesting planting system (RFRHP) where runoff is collected by plastic mulched ridges can improve the crop productivity in the semiarid areas of northwest China. During 2012–2014, we performed a field evaluation of the influence of RFRHP with supplementary irrigation (RI) on the water irrigation use and water use efficiency by maize in a semiarid climate using the following treatments: (1) no supplementary irrigation (RN); (2) irrigation during the trumpeting stage (RB); (3) irrigation during the blooming stage (RF); (4) irrigation during the trumpeting and blooming stages (RBF); and (4) traditional flat planting with border irrigation (CK). We found that although the irrigation volume was double under CK, the soil water content in the 0–120 cm soil layer did not differ significantly between the RFRHP with supplementary irrigation treatments and CK. The RFRHP with supplementary irrigation treatments reduced the irrigation water volume required (750–1125 m3 hm−2) and alleviated drought stress during key maize growth periods. The biomass, grain yield, and water use efficiency were significantly higher under RFRHP with supplementary irrigation, i.e., 6.0–8.7%, 15.4–25.8%, and 34.9–39.2% higher compared with CK, respectively, and 3.8–6.4%, 4.8–14.2%, and 9.2–12.7% higher compared with RFRHP with no supplementary irrigation. Under RFRHP with supplementary irrigation treatments, the irrigation water use efficiency was 1.5–3.9 times higher than that under CK. The irrigation water productivity levels under the RFRHP with supplementary irrigation treatments were ranked as follows: trumpeting stage > trumpeting and blooming stages > blooming stage. Compared with CK, RFRHP with supplementary irrigation significantly increased the out/input ratio and net income by 13.1–26.9% and 2600–3762 Chinese Yuan hm−2, respectively.

Phosphorus losses under heavy rain from the sloping farmlands in the purple hilly region of Southwestern China

Phosphorus (P) and sediment loss through runoffs to surface and ground water represent a risk to human and environmental health. The objective of this work was to understand the mechanisms of P loss under heavy rain from the purple soil of sloping farmlands. The work was carried out with simulated rainfall experiment at different maize growth stages. The combination of three factors was studied: tillage methods (flat planting, longitudinal ridge, and cross-ridge), slope gradients (10°, 15°, and 20°), and maize growth stages (seedling stage, elongation stage, tasseling stage, and maturity stage). Surface runoff, subsurface runoff, sediment, P content in runoff, and sediment were determined. The rate of sediment yield was positively and non-linearly correlated with the runoff shear force and increased quickly when using the longitudinal ridge tillage method. Longitudinal ridge and 20° slope croplands showed greater erodibility, which resulted in higher runoff, sediment yield, and associated P loss. Total phosphorus (TP) and available phosphorus (AP) losses during the entire growth period were 17.58 mg m−2 and 32.86 mg m−2, in the longitudinal ride on 20° slope. Cross-ridge treatment can effectively prevent the loss of P. The P loss occurred violently on 20° slope, and there was little difference in the P loss between 10° and 15° slopes. Dissolved total phosphorus (DTP) loss dominated the TP loss in runoff, accounting for more than 55.58% of the DTP losses in all the treatments. These results indicate the application of flat planting and cross-ridge tillage in croplands with less than 20° slope, as these will minimize the pollution of soil and water resources by reducing P loss in runoff and sediment.

Seed weight predicts seedling emergence, and extremely acid soil and low availability of Phosphorus are associated with poor plant performances in Lepidium meyenii Walpers (maca)

Lepidium meyenii Walpers (maca) is a Peruvian species cultivated in the high Andean region (ca. 4000 m.a.s.l.), highly praised for the nutritional properties of its hypocotyl. The benefits to human health and their relationship with the hypocotyl have been well investigated. However, few studies have addressed the factors affecting field crop performance and the improvement of agronomic practices. Here we evaluate the effect of soil properties (humidity, temperature, and fertility) and sowing method (ridge-furrow system and flat planting) on the biological performance of five seed accessions of maca in 6 experimental plots along an altitudinal gradient (3554–4442 m.a.s.l.). Plots located at both the lowest and highest altitudes had lower plant survival, vegetative growth, and hypocotyl size. Most of the differences among plots could be attributed to the acidity and the concentration of available phosphorus in the soil. In addition, low soil temperature and humidity negatively affected crop performance at different stages of plant development. The ridge-furrow system appeared to promote plant growth, although it did not favor plant survival under the unexpected climatic conditions experienced. Finally, seed weight was found to be a good predictor of seedling emergence and plant survival.

Impact of farmland mulching practices on the soil bacterial community structure in the semiarid area of the loess plateau in China

Farmland mulching is widely used to preserve soil moisture and increase crop yield in the semiarid region of the Loess Plateau. However, the effect of different farmland mulching on soil bacterial communities is not clear. Therefore, the impact of a 5-year field management practice (surface mulching) on the soil bacterial communities was studied in dryland farmland of the Loess Plateau by using Illumina sequencing of the 16S rRNA gene. The following treatments were investigated: (1) ridge-furrow mulching pattern; (2) flat plastic film mulching; (3) flat biodegradable film mulching; (4) flat straw mulching; and (5) control (CK), conventional flat planting without mulch. All farmland mulching increased the diversity of soil bacteria and the diversity was greatest under the plastic film treatment. The dominant phyla across all soil samples were Proteobacteria, Acidobacteria, and Actinobacteria. Cluster analyses showed that bacterial communities under mulching treatments were different from that of CK. The bacterial community composition of plastic film and straw mulching treatments, biodegradable film and ridge-furrow mulching treatments were similar at the phylum level. Spearman correlation analysis indicated that the response of bacterial alpha-diversity was mainly negatively associated with the soil organic carbon and total nitrogen. The Mantel test showed that the beta-diversity depended primarily on the soil total nitrogen and soil temperature. The changes of the bacterial community distribution were significantly related to the soil moisture, which varied significantly with a range of 9.8–17.3 between treatments. These results indicated that soil properties changed after long-term farmland mulching, and these changes were related to soil bacterial diversity and community structure. According to this study, flat plastic firm mulching was found to being a good option for increasing soil bacterial diversity and richness and thereby potentially stabilize functional stability of soil biological processes.

Optimized ridge–furrow with plastic film mulching system to use precipitation efficiently for winter wheat production in dry semi–humid areas

Ridge–furrow with plastic film mulching (RFPFM), a rainwater harvesting system, is receiving increasing attention worldwide. However, its usefulness in semi–humid regions with irrigation capabilities remains unclear. In addition, the optimal ridge–to–furrow ratios and nitrogen (N) application rates are unknown. In this study, we investigated five different planting patterns (i.e., rain–fed flat planting [CK], RFPFM practices with three different ridge–to–furrow ratios [20:40, RFPFM20; 30:30, RFPFM30; and 40:20, RFPFM40], and RFPFM plus supplemental irrigation [RFPFM + SI]) under two N application rates (75 and 225 kg·ha–1) in winter wheat over two years. RFPFM practices led to increased soil temperature in the ridges at the seedling stage and the retention of more water in the furrows throughout the two growing seasons. The improved hydrothermal characteristics of RFPFM plots led to early and stable seedling establishment, resulting in higher grain yields, water use efficiency (WUE), and net revenues. Grain yields were higher with RFPFM20, RFPFM30, RFPFM40, and RFPFM + SI practices than with CK by 28.3%, 37.2%, 55.6%, and 100.4%, respectively, averaged for both N rates over the two years. Additionally, WUE was higher by 22.6%, 28.3%, 40.5%, and 9.3%, respectively. Increased ridge–to–furrow ratios affected micro–topography, as evidenced by improvements in hydrothermal features, grain yields, WUE, and net revenues. Overall, we recommend RFPFM40, the widest ridge, as a promising water–saving and economical practice for winter wheat production in dry semi–humid areas. Supplemental irrigation could be considered in RFPFM practices to alleviate drought stress in dry years (<150 mm precipitation) to increase grain yields, WUE, and net economic benefits. Technological advancements, such as innovative mechanization to reduce extensive labor costs, are required to boost the adoption of RFPFM practices, fully exploit its economic and social benefits, and prioritize environmental sustainability.

Film mulched furrow-ridge water harvesting planting improves agronomic productivity and water use efficiency in Rainfed Areas

Film fully-mulched ridge–furrow (FMRF) water harvesting, film mulched conventional flat planting with one-half (FMCF) and two-thirds (FTMCF) has been widely adopted in Northern China. However, it is unclear whether sustainability are. An 8-year corn yield in these three systems was investigated at Zhenyuan of East Gansu in 2008 to 2015, and a 4-year location study with FMRF and FMCF, three corn hybrids, and three densities was conducted at Pengyang of South Ningxia from 2012 to 2015. The results indicated that FMRF with rain-harvesting efficiency of 65.7%–82.7% makes rainwater infiltrate deep soil and soil moisture double increase in furrow root-zone. The 8-year average grain yield increased by 22.7% in FMRF and 14.5% in FTMCF compared with FMCF. In the 4-year field trail, rainfall and its seasonal distribution highly impacted grain yield and water-use efficiency (WUE), but order of importance for grain yield and WUE increases were density > mulching type > hybrid. Grain yield and WUE increased by 20.0% and 3.45 kg ha−1 mm−1 and 12.0% and 2.97 kg ha-1 mm−1 from low to medium density and medium to high density; ET and grain yield and WUE increased simultaneously from low to medium density, however grain yield and WUE improved but ET changed slightly from medium to high. Soil water content of the 0–200 cm layer during growing season was always higher in FMRF than in FMCF, and ET did not differ. FMRF kept more than 50–90 mm soil water in the 0–200 cm during grain filling period. Neither higher grain yield in the FMRF depleted soil water, nor resulted in soil desiccation regardless of the year of precipitation. On the contrary, the FMRF kept much more water into soil layers at corn harvest, and negative effects to soil water balance were not observed. Thus, the package of FMRF combining with close planting and density tolerance hybrids is climate-smart technique for coping with droughts and ensuring corn yield in rainfed areas.

Ridge-furrow with film mulching practice ameliorates soil microbial metabolic activity and carbon utilization in rhizosphere soil of rapeseed (Brassica napus L.)

The farming practices of ridge-furrow with film mulching (RFFM) have been extensively reported as a valuable technique for improving crop productivity and enhancing water-use efficiency. However, research on the high-yield mechanism of RFFM measures under drought stress from the perspective of microbial diversity has been scared. Field experiments were conducted to analyze the effects of conventional flat planting (FP), no film mulching (NR), white polyethylene film mulching (WR), black polyethylene film mulching (BR), and biodegradable film mulching (BDR) with 40 and 80 cm furrow width levels on soil temperature, soil water storage (SWS), microbial carbon utilization, and yield of winter oilseed rape. The RFFM significantly increased the SWS as well as rapeseed yield and yield components. However, these treatments did not cause obvious differences in soil temperature. A relative high value of average color change rate (AWCD) was observed during the incubation time of 24–216 h, and it reached the peak value at 240 h. The AWCD in the furrow with 80 cm width was greater than that of 40 cm. The RFFM also could improve the utilization intensities of soil microorganism on the carbon sources of carbohydrates, amino acids, and miscellaneous in rapeseed rhizosphere. This result was consistent with that of the principal component analysis. The Shannon–Wiener diversity index, Simpson’s diversity index, and Shannon–Wiener evenness in BDR40, BR40, and BR80 were significantly higher than other treatments, respectively. In addition, correlation analysis results suggested that the indicator of affecting the diversity of carbon source was mainly due to the water storage capacity. The methods of film mulching have a remarkable effect on microbial diversity. The yield of BR and BDR were significantly higher than other treatments. Compared with FP, RFFM increased rapeseed yield by 9.61–86.10%. In the year of less rainfall, production has decreased in comparison with the first season, while BDR80 guarantees continuous high yield and substantially promoted carbon utilization and soil microbial diversity. Soil microbial diversity is positively correlated with soil water content, which is beneficial to increase production. Wider furrow (80 cm) is recommended a sustainable high-yield method due to convenient labor in the region in Southwest China.

Effects of different long-term farmland mulching practices on the loessial soil fungal community in a semiarid region of China

The Northwest Loess Plateau is a typical area of dryland agricultural production in China. Farmland mulching is often used to preserve the soil moisture and increase crop yields. However, the impacts of long-term farmland mulching practices on the soil fungal communities in the loessial soil in semiarid areas of China were less explored. Thus, we investigated the variations in the soil fungal communities under different mulching patterns using high-throughput sequencing to understand how different mulching practices affect these communities. The following treatments were investigated: ridge-furrow mulching pattern (R), flat plastic film mulching (P), flat biodegradable film mulching (B), flat straw mulching (S), and conventional flat planting without mulching as a control (CK). Farmland mulching practices significantly affected the soil fungal diversity and community structure by changing the soil properties. Compared with CK, the P and S treatments significantly increased the soil fungal diversity, thereby suggesting that these practices provided the most suitable growth environment for fungi. The soil moisture and nitrate nitrogen (NO3-N) content were the most important factors that affected the fungal diversity. Nonmetric multidimensional scaling ordination showed that the fungal communities in CK were separated from those in R and B treatments and closely clustered with the communities in the P and S treatments, thereby suggesting that the fungal community compositions differed slightly between the P and S treatments and the CK treatment, but the soil fungal community compositions in the R and B treatments differed significantly from that in CK. In addition, the fungal community composition depended primarily on the soil temperature and NO3-N. These results indicate that different farmland mulching practices affected the soil moisture, soil temperature, and NO3-N to change the soil fungal community distribution patterns in this region. Overall, the soil fungal diversity and abundance were both higher in the P treatment than the other treatments. Therefore, flat plastic film mulching is recommended for semiarid areas.

Biodegradable mulching film with an optimum degradation rate improves soil environment and enhances maize growth

Biodegradable film is considered as a promising alternative to polyethylene film in rainfed farming of arid and semi-arid regions, since the widespread use of polyethylene film has led to many negative effects, such as environmental pollution and land degeneration. In order to identify an optimal biodegradable film for summer maize, field experiments were conducted to investigate the effects of biodegradable films with different degradation rates on soil water storage (SWS), soil temperature, soil organic carbon (SOC), the growth stages, grain yield, water use efficiency (WUE), and economic return over three growing seasons from 2014 to 2016. Three biodegradable films one with a fast degradation rate (B1), one with a moderate degradation rate (B2), and one with a slow degradation rate (B3), were compared with a polyethylene film (P) and a flat planting system without film mulching was used as the control (CK). The degradation progress of the three types of biodegradable film (B1, B2, and B3) was on time or delayed by about 10 days during normal years (2014 and 2015 seasons) and advanced by 10–20 days during the extreme year (2016 season, plants affected by both lodging and high temperature). Soil temperature and SWS increased significantly under B1 (3.6 °C higher at 5 cm and 2.4 °C higher at 25 cm) and B2 (3.7 °C higher at 5 cm and 2.3 °C higher at 25 cm), compared with CK before the biodegradable film degraded. However, there was no difference in soil temperature and SWS after the biodegradable films B1 and B2 had degraded. The B3 and P treatments led to similar soil temperatures and SWS values throughout the maize seasons. After 3 years of experiments, the SOC levels ranked from high to low were 2.85%, 5.30%, 11.72%, and 15.07% higher in CK than that in B1, B2, B3, and P, respectively. The season length was the longest in B2 (117, 117 and 112 d) for all three seasons. Average grain yield, WUE, and net revenue in B2 were 18.40%, 25.10% and 32.97%, 11.90%, 6.62% and 20.46%, 11.43%, 6.82% and 15.71%, and 32.50%, 45.64% and 41.05% higher than in B1, B3, P, and CK, respectively. The results suggested that biodegradable film with a moderate degradation rate could improve the soil environment, promote maize growth, increase net revenue and reduce loss of SOC relative to B1, B3 (no significant difference with B1 in SOC level) and P. Therefore, B2 was the best biodegradable film for summer maize production in regions with sub-humid drought-prone climates.

Ridge-furrow mulching system regulates diurnal temperature amplitude and wetting-drying alternation behavior in soil to promote maize growth and water use in a semiarid region

Utilizing the ridge- furrow mulching system with plastic film (RFMS) is an effective strategy for improving crop productivity in semiarid areas. However, the key mechanism by which RFMS drives spatiotemporal hydrothermal variation of soil to positively affect crop production is not well-defined, and a better understanding of this mechanism could guide RFMS optimization. A two-year field experiment was conducted with three planting treatments: 1) the RFMS with high coverage ratio, 50 cm mulched ridge:10 cm bare furrow, RFH; 2) the RFMS with low coverage ratio, 60 cm mulched ridge:60 cm bare furrow, RFL; and 3) flat planting without mulching as the control treatment, CK. The results showed that RFMS increased topsoil temperature by 1.0–2.5 °C during the day (08:00–20:00) and 1.6–3.4 °C at night (20:00–08:00), respectively, compared with CK, which led to a decrease of 0.4–1.3 °C in diurnal temperature amplitude, but indicated a strong positive impact on maize growth in the thermally deficient study area. In addition, RFMS drove the spatio-temporal alternation of soil wetting and drying (alternation of high and low SWC) relative to CK, indicating an efficient water use strategy that significantly reduces soil evaporation but promotes the plant transpiration during water sensitive period. These effects in RFH were significantly greater than those in RFL due to its significantly enhanced water infiltration, suppressed evaporation and reduced heat loss, which stimulated vigorous crop growth. This study suggested that, compared to CK, RFH was more efficient than RFL to improve maize production, which increased these amplitudes from 43.1% to 59.2% in grain yield increase, from 38.5% to 57.4% in water use efficiency (WUE) increase and from 71.7% to 95.0% in economic benefit increase, respectively. Therefore RFH can be considered as a superior technique for overcoming simultaneous drought and cold stresses in northwestern China.