Ridge-furrow System Research Articles

How biochar curbs the negative impacts of plastic mulching on soil enzymes and microorganisms while elevating crop yields in ridge-furrow systems

Ridge-furrow tillage is an important tillage and yield enhancement method used in dry farming areas; however, the spatial characteristics of the soil microenvironment under ridge-furrow tillage and the response of crop yields to mulching and biochar addition are not known. In this study, we conducted a three-year field experiment in which mulch and biochar, alone or combined, were introduced into ridge-furrow tillage system to explore their interactive effects on soil enzyme activities, bacterial communities, functional genes, and crop yields. The findings reveal significant spatial differences in soil physicochemical composition, enzyme activity, microbial communities, and functional genes under ridge-furrow tillage, which are further exacerbated by the addition of mulching and biochar. Under the premise of ridge-furrow tillage, both mulching and biochar addition reduce the α diversity of bacterial communities. Mulching simplifies the bacterial network, while biochar addition has the opposite effect. Mulching and biochar addition increase the relative abundance of carbon, nitrogen, and phosphorus functional genes and accelerate nutrient cycling, especially on the ridges. Mulching significantly improves crop yield but is detrimental to alkaline phosphatase activity and the abundance of the gene function. The addition of biochar mitigates the harm of mulching and further increases alfalfa yield. These findings not only provide scientific support for optimizing ridge-furrow tillage but also deepen our comprehensive understanding of the soil biochemical environment after the addition of mulching and biochar, further revealing their positive effects on yield formation.

Evaluating corn production under different plant spacings through integrated modeling approach and simulating its future response under climate change scenarios

The use of advanced resource conservation techniques is the need of time for higher crop production under the challenges of water scarcity and climate change. The present study was planned (1) to evaluate different plant spacing of corn, sown under raised bed planting (RBP) for higher productivity, (2) calibrate APSIM model for experimental treatments and (3) simulate future (2022–2100) crop response under different scenarios of climate change. The two-year research experiments were conducted on corn with four different plant spacings (S1:15 cm, S2:17.5 cm, S3:20 cm and S4:22.5 cm) under RBP. The crop response was evaluated in terms of leaf area index (LAI), plant height, flowering date, grains per cob, grain yield, biomass yield, harvest index (HI) and water productivity. The S1 treatment produced the highest productivity in terms of grain yield (7.16 Mg/hm2), biomass yield (16.57 Mg/hm2), HI (0.44) and water productivity (1.33 kg/m3). APSIM model was calibrated and its ability to simulate crop response during validation was confirmed from the values of RMSE, NRMSE, R2, CRM and NSE as 0.4, 0.21, 0.83, 0.04 and 0.68 for grain yield. The RMSE and NRMSE were 0.79 and 0.14 for biomass yield. The value of R2 ranged from 0.69 to 0.85, CRM from –0.03 to 0.005, NSE from 0.69 to 0.86 for biomass yield, plant height and LAI. During scenario simulations, the model run was performed against different plant spacing for optimization and results revealed that 10 cm plant spacing produced highest corn yield and growth parameters. Further simulations (2022–2100) were performed using climatic data, acquired from different general circulation model (GCMs) for two rcps (4.5 and 8.5) and results revealed the reduction in grain and biomass yields by 8–14 % and 10–28 %, respectively against different data sources (GCMs). Optimized plant spacing (10 cm) under RBP produced 35.5 % more grain yield and 29.3 % more biomass yield than that under control treatment (ridge-furrow system). Based on the research findings, it is recommended that conservation technique like RBP needs to be adopted in semi-arid regions to mitigate the impact of climate change in terms of future temperature rise for better corn production.

Mulched Drip Fertigation with Growth Inhibitors Reduces Bundle-Sheath Cell Leakage and Improves Photosynthesis Capacity and Barley Production in Semi-Arid Regions.

A better understanding of the factors that reduce bundle-sheath cell leakage to CO2 (Փ), enhance 13C carbon isotope discrimination, and enhance the photosynthetic capacity of barley leaves will be useful to develop a nutrient- and water-saving strategy for dry-land farming systems. Therefore, barley plants were exposed to a novel nitrification inhibitor (NI) (3,4-dimethyl-1H-pyrazol-1-yl succinic acid) (DMPSA) and a urease inhibitor (UI) (N-butyl thiophosphorictriamide (NBPT)) with mulched drip fertigation treatments, which included HF (high-drip fertigation (370 mm) under a ridge furrow system), MF (75% of HF, moderate-drip fertigation under a ridge furrow system), LF (50% of HF, low-drip fertigation under a ridge furrow system), and TP (traditional planting with no inhibitors or drip fertigation strategies). The results indicated that the nitrification inhibitor combined with mulched drip fertigation significantly reduced bundle-sheath cell leakage to CO2 (Փ) as a result of increased soil water content; this was demonstrated by the light and CO2 response curves of the photosynthesis capacity (An), the apparent quantum efficiency (α), and the 13C-photosynthate distribution. In the inhibitor-based strategy, the use of the urease and nitrification inhibitors reduced Փ by 35% and 39% compared with TP. In the NI-HF strategy, it was found that barley could retain the maximum photosynthesis capacity by increasing the leaf area index (LAI), An, rubisco content, soluble protein, dry matter per plant, and productivity. The CO2 and light response curves were considerably improved in the NI-HF and NI-MF treatments due to a higher 13C carbon isotope (Δ‱), respiration rate (Rd), and Ci/Ca, therefore obtaining the minimum Փ value. With both inhibitors, there was a significant difference between HF and LF drip fertigation. The NI-MF treatment significantly increased the grain yield, total chlorophyll content, WUE, and NUE by 52%, 47%, 57%, and 45%, respectively. Collectively, the results suggest that the new nitrification inhibitor (DMPSA) with HF or MF mulched drip fertigation could be promoted in semi-arid regions in order to mitigate bundle-sheath cell leakage to CO2 (Փ), without negatively affecting barley production and leading to the nutrient and water use efficiency of barley.

Effect of Nitrogen Management on Wheat Yield, Water and Nitrogen Utilization, and Economic Benefits under Ridge-Furrow Cropping System with Supplementary Irrigation

Supplemental irrigation under a ridge-furrow (RF) cropping system is a valuable cropping practice that balances resource efficiency and high crop yield. However, the effects of nitrogen management on crop growth, yield formation, and economic benefits under RF systems have not been clearly investigated. In this study, the experiment was designed with three experimental factorials, including three cropping systems (RF, RF cropping with 80 mm irrigation; TF1, traditional flat cropping with 200 mm irrigation; and TF2, traditional flat cropping with 80 mm irrigation), two nitrogen application rates (NL, 180 kg N ha−1; NH, 240 kg N ha−1), and two fertilizer application models (B, all nitrogen fertilizers were applied basally at the pre-sowing stage; BT, nitrogen fertilizer was applied at both the pre-sowing and jointing stages at a ratio of 1:1). A two-year field experiment was conducted to investigate the effects of nitrogen fertilizer management on wheat yield, water and nitrogen utilization, and economic benefits under the RF cropping system. The results showed that the RF system significantly increased the soil moisture content and improved the water productivity (WP) and grain yield of wheat. Nitrogen reduction (NL) under the RF system did not affect the water use of the wheat compared with traditional high nitrogen application (NH) but increased the nitrogen uptake and fertilizer productivity of the wheat. Although NL led to a reduction in aboveground dry matter accumulation, it did not significantly affect the yield of wheat but increased the net income of wheat cultivation. Under NL conditions, the BT nitrogen application model promoted nitrogen uptake in wheat and ameliorated the reduction in grain protein content due to plastic film mulching, and this model is an integrated planting practice that trades off wheat yield and quality. These findings suggest that NLBT is a promising and recommendable cropping practice under RF systems considering resource utilization, high yield and quality, and economic efficiency.

Exploring Optimal Cropping System to Improve the Water Use Efficiency and Soil Water Restoration after Lucerne-to-Crop Conversion in the Semiarid Environment

Due to depleting water supplies and the cultivation of high water-demanding crops such as lucerne, the effect of water deficits in crop production has become a major concern, especially in semiarid regions of China. A six-year field experiment (2012–2018) was conducted to evaluate soil water recovery and soil fertility after lucerne-to-crop conversions on the western Loess Plateau of China. Six rotation treatments (lucerne initially grew from 2003 to 2012 followed by the rotation of other crops or fallow until assessments in 2018) were: (1) lucerne (Medicago sativa L.)–lucerne (L-L); (2) lucerne–fallow (L-F); (3) lucerne–wheat (Triticum aestivum L.) (L-W); (4) lucerne–corn (Zea mays L.) (L-C); (6) lucerne–potato (Solanum tuberosum L.) (L-P); and (6) lucerne–millet (Setaria italica) (L-M). The same crops were grown each year after cultivation during 2013–2018. According to the findings, all rotation types gradually increased the soil water content, with the 0–110 cm soil layer experiencing the maximum soil water replenishment rate, followed by the 110–200 and 200–300 cm soil layers. After converting lucerne to crops, the amount of organic carbon, total nitrogen, and mineral nitrogen in the soil decreased, whereas total phosphorus and accessible phosphorus increased. Soil bulk density was reduced under rotation treatments. Soil water absolute restoration index was the highest under L-F, followed by L-C, L-W, L-P, and L-M. The rate of soil water recovery was 39.5, 33.0, 33.7, 33.5, 29, and 8.2 mm yr−1 under L-F, L-W, L-C, L-P, L-M, and L-L, respectively. The net economic return was greatest under L-C, followed by L-L, L-W, L-P, and L-M. From the analysis of the long-term experimental results, this study shows that the effect of soil water restoration is greatest when continuous alfalfa is converted into wheat, corn, and potato or fallow after 9 years. When the economic benefits and soil moisture recovery are considered comprehensively, corn sown in a ridge–furrow system with fully plastic film annual mulching is the most suitable field management practice after lucerne-to-crop conversion on the western Loess Plateau of China.

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.

Yield structure and water use efficiency of summer maize (Zea mays L.) under wide ridge-furrow planting in the furrow irrigation process

ABSTRACT The impact of wide ridge-furrow planting on maize production are mostly unexplored. The field experiment was conducted to study the effect of four ridge width on growth and water use efficiency (WUE) of maize (Xianyu 335) with same furrow spacing and basin planting with same spacing as conventional planting (CP). Compared with the CP, ridge-furrow (RF) increased plant height but reduced stem diameter and dry matter weight. The wide ridge under RF was beneficial to the high leaf area and dry matter accumulation. However, the least plant spacing generated stress on stem growth with a wider ridge (RF180). The maximum grain yield (6573 kg ha−1) and WUE (23.0 kg mm−1 ha−1) were obtained under RF120, which were increased by 15.9% and 33.9% compared with CP. Irrigation efficiency and irrigation water use efficiency (IWUE) under RF system was improved 1.20–1.43 times and 1.89–2.45 times compared with CP, which was mainly due to the lower volume of irrigation water (decreased by 34.5–42.9%) under the RF system. Our results highlight that the RF method can be used as a water-saving method with ridge width up to 120 cm that lead to high yields of maize.

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

Soil erosion control and wheat productivity are improved by a developed ridge-furrow and reservoir tillage systems

ABSTRACT Soil erosion and drought are significant environmental hazards for crop production in the northwestern coastal zone of Egypt, leading to increased soil resources degradation. In-situ rainwater harvesting techniques by changing the micro-topography of soil via tillage practices can increase runoff retention and improve soil productivity. In this study, field trials were conducted on a sandy loam soil to determine the effects of four tillage systems [integrated ridge-furrow tillage (RFT), integrated reservoir tillage (RT), conventional tillage (CT), and No tillage (NT)] on soil bulk density, volumetric water content, runoff, soil loss, precipitation use efficiency, and winter wheat yield during two growing seasons under-rainfed conditions. The results indicated that tillage systems significantly affected soil properties, precipitation use efficiency and wheat yield in the order of: RFT > RT > CT > NT. Compared with the CT, the mean runoff with the developed RFT and RT was significantly decreased by 55.4% and 40.3%, respectively. Meanwhile, the precipitation use efficiency increased by 18.1% and 9.5%, respectively. By taking into account the stability of soil productivity along with environmental protection, it is suggested that the RFT and RT are the tillage systems that can efficiently increase the availability of soil water and, consequently, wheat yield.

Water management increased rhizosphere redox potential and decreased Cd uptake in a low-Cd rice cultivar but decreased redox potential and increased Cd uptake in a high-Cd rice cultivar under intercropping

Excessive Cd in crop grains is toxic to humans. We conducted a field experiment to investigate the effects of intercropping on rice yield and grain Cd content as well as a pot experiment to compare the rhizosphere redox potentials of low-Cd ‘Zhuliangyou 189’ and the neighboring high-Cd ‘Changxianggu’ that mediated Cd uptake in a flooded or a ridge–furrow system. In the field experiment, Cd removal from contaminated soil in intercropping was 1.44 times higher than that in monoculture of Zhuliangyou 189. In both Zhuliangyou 189 and Changxianggu, intercropping improved the grain yield and decreased grain Cd content. In the pot experiment, Fe plaque amount was strongly and positively correlated with bulk soil Fe(II) content, root H2O2 concentration, and Fe(II)-oxidizing ability of root bacteria but negatively correlated with Fe(II)-oxidizing ability of bulk soil bacteria and root Cd content. In Zhuliangyou 189, intercropping increased root H2O2 concentration, rhizosphere redox potential, iron plaque amount but decreased Cd bioavailability, Fe(II)-oxidizing ability of bulk soil bacteria, and organ Cd content. In the flooded system, Zhuliangyou 189 showed higher bulk soil Fe(II) content than Changxianggu. In the ridge–furrow system, ridges decreased the Fe(II)-oxidizing ability of root and bulk soil bacteria, thereby decreasing Fe plaque amount and increasing organ Cd content of rice. In both monoculture and intercropping systems, rice cultivars planted on ridges showed higher Cd bioavailability and lower bulk boil Fe(II) content than those planted in furrows.

Dual plastic film and straw mulching boosts wheat productivity and soil quality under the El Nino in semiarid Kenya

The extreme climate events such as El Nino seriously threaten crop production and agro-ecological sustainability because of the aggravated environmental stresses worldwide, particularly in sub-Saharan Africa. To address this issue, we investigated the effects of dual plastic film and straw mulching in ridge-furrow (RF) system on wheat productivity, soil carbon and nitrogen stocks in a semiarid area in Kenya from 2015 to 2017. The experimental site represents a typical semiarid continental monsoon climate, and soil type is chromic vertisols. Field experiment with randomized block design consisted of six RF treatments as follows: 1) dual black plastic film and straw mulching (RFbS), 2) dual transparent plastic film and straw mulching (RFtS), 3) sole black plastic film mulching (RFb), 4) sole transparent plastic mulching RF (RFt), 5) sole straw mulching (RFS) and 6) no mulching (CK). The results indicated that seasonal dynamics of rainfall and air temperature fit in with the weather type of El Nino over four growing seasons. RFbS, RFtS, RFb and RFt significantly increased soil water storage (SWS), topsoil temperature, aboveground biomass, grain yield and water use efficiency across four growing seasons (p < 0.05) as compared with CK. Among all the treatments, RFbS and RFtS achieved the greatest SWS, AgB, grain yield and WUE, owing to improved soil hydro-thermal status in both treatments. Critically, RFbS and RFtS significantly improved soil organic carbon and total nitrogen, soil bulk density and the C:N ratio following four growing seasons, comparing with other treatments (p < 0.05). Besides, RFbS and RFtS gave the highest economic returns among all treatments. For the first time, we found that dual plastic film and straw mulching could serve as a sustainable land management to boost wheat productivity and improve soil quality under El Nino in semiarid areas of SSA.

Impact of conservation practices on soil hydrothermal properties and crop water use efficiency in a dry agricultural region of the tibetan plateau

Mulching combined with a ridge-furrow system (MRFS) has been regarded as a suitable management method for alleviating the hydrothermal limitation of crop production in semiarid regions. However, whether this practice can be extended to high altitude alpine agricultural regions remains unclear. In order to evaluate the effectiveness of MRFS in improving soil hydrothermal properties, crop yield and water use efficiency (WUE) in alpine regions, a field experiment was conducted on the Tibetan Plateau (TP) with three treatments including: mulching with ridge-furrowing (MR), mulching with flat planting (MF), and bare soil with flat planting as a control (CK). The results indicated that MR performed best in terms of increasing soil water content within a depth of 10–50 cm after irrigation and precipitation at the sprout stage, and in maintaining significantly higher (P < 0.05) soil water storage (SWS) in the 50–110 cm soil layer throughout the whole growth period. Thermal performance in the 20 cm soil depth was also best in MR, with an average temperature increase of 1.1 °C compared to CK. Evaporation was significantly lower (P < 0.05) in MR compared with CK, although the highest evapotranspiration rate was observed in MR. Higher values for plant height, ground diameter, leaf area index (LAI) and fine root length density (FRLD) were found in MR. In comparison with CK, yield was 16 % higher, WUE was improved by 3 % and benefit was improved by 11.7 %. These results suggested that MR represents an efficient planting pattern for improving soil hydrothermal properties and crop yield on the TP.

Subsoiling increases grain yield, water use efficiency, and economic return of maize under a fully mulched ridge-furrow system in a semiarid environment in China

After widespread application of the fully mulched ridge-furrow system, maize (Zea mays L.) has become a newly dominant crop in the semiarid Loess Plateau of China. Maximization of water use efficiency (WUE) through optimal farming practice are of great importance for sustainable intensification of maize production in this region. In this study, the impact of different tillage practices on soil quality, soil water, grain yield, WUE, and net economic return in a fully mulched ridge-furrow system were examined in a five-year field experiment, to optimize tillage practice for maize production in the area. Four tillage practices (CT, conventional tillage; NT, no-tillage; RT, rotary tillage; SS, subsoiling) were assessed. Compared to CT, SS reduced soil bulk density and penetration resistance, and increased saturated hydraulic conductivity and the percentage of macro-aggregates (≥ 0.25 mm) in the 0–30 cm soil layers, but NT and RT had the opposite effects to above soil physical properties except for macro-aggregates. Tillage practice did not significantly affect soil water storage, evapotranspiration, but annual soil water balance was lowest under SS, followed by CT, NT, and RT. SS increased soil organic C, mineral N and available P at 0−30 cm soil layer compared to CT. Grain yield and WUE under SS were increased by 12 and 15 % compared to CT, NT and RT had no significant effect on grain yield and WUE. Net economic return under NT and SS were increased by 42 and 23 % respectively compare to CT. These results demonstrated that subsoiling could improve grain yield, WUE, and net economic return of dryland maize by improving soil quality and mitigating soil water depletion. In the long-run, although no-tillage increased net economic return, it may not be sufficient to maintain yield and WUE due to deteriorated soil properties and accelerated soil water depletion. Thereby, subsoiling is optimal tillage practice for sustainable intensification of maize production in the semiarid Loess Plateau of China.

Discrimination of soil losses between ridge and furrow in longitudinal ridge-tillage under simulated upslope inflow and rainfall

Longitudinal ridge-tillage greatly enhances hillslope soil erosion due to increased flow concentration in furrows and sediment delivery from ridge sideslopes. Currently, contributions of upslope inflow and rainfall to soil loss and identification of sediment sources in a ridge-furrow system are still unclear. A set of experiments on 10-m long, 2-m wide field runoff plots at a 5° slope gradient were conducted in the Chinese Mollisol region to quantify the effects of upslope inflow and rainfall on hillslope erosion and to discriminate sediment contributions between ridges and furrows in a longitudinal ridge-tillage system. The experimental treatments included five upslope inflow rates alone (10, 20, 30, 40 and 50 L min−1), two rainfall intensities alone (50 and 100 mm h−1) and the five inflow rates combined with the two rainfall intensities. A stereoscopic photogrammetry method was used to measure micro-topographic conditions before and after each run. The results showed that, compared with the inflow-only treatments, soil losses increased by 1.4–5.2 times and 2.5–14.0 times under the combined treatments of the five inflow rates and two rainfall intensities, respectively. The contributions of the synergistic effects increased with the increase of rainfall intensity. Moreover, in the five upslope inflow-only treatments, soil erosion mainly occurred in the bottom of furrows and ridge toe slopes; while for the combined treatments, ridge sideslope erosion dominated as soil loss from ridge areas accounted for 51.3 %–60.9 % and 53.0 %–61.8 % for the 50 and 100 mm h−1 rainfall intensities, respectively. Therefore, ridge sideslope erosion may be the main sediment source in the longitudinal ridge-tillage system under the bare conditions.

Enhance root-bleeding sap flow and root lodging resistance of maize under a combination of nitrogen strategies and farming practices

A cultivation technique in combination of nutrient strategies has not been implemented on root growth, root-bleeding sap, lodging resistance and production of corn. Therefore, we conducted field trials implementing different cultivation techniques (ridge-furrow system with film covered (RF), ridge-furrow system with soil crust (SC), and flat soil planting system with no ridge and no cover (TF); with four nitrogen levels: 300 kg N ha−1 (3); 200 kg N ha−1 (2); 100 kg N ha−1 (1) and 0 kg N ha−1 (0), during 2015–2016. The aim of this work was to improve soil water storage, yield components, and production through regulating root growth and lodging resistance. The results showed that the RF system under different nutrient levels had significantly improved soil water storage, yield components which led to promote the development of roots in deep soil (0–50 cm) than that of SC and TF planting. The RF2 treatment significantly increased the root volume density (RVD), root weight density (RWD), and root diameter at various growth stages and attained the maximum value at 125 DAP (except root diameter) than that of TF2 treatment. The root surface area density (RSD) and root length density (RLD) were significantly increased in the upper 10–60 cm soil layer under the RF and SC cultivation patterns during silking and maturity stages than that of TF planting under different N levels. However, among the different treatments, there was non-significant variation in RSD and RLD at below 70 cm soil profile. The RF2 and SC2 considerably increased the root dry weight, and the root bleeding sap during entire growth stages of maize crop than that of TF2 planting. The RF system with different N levels delayed roots senescence in the later growth stage, and the production was significantly increased compared with SC and TF planting. Compared with SC2 and TF2 treatment, the RF2 treatment significantly increased the grain yield 5.7 t ha−1 (104%) and reduces root (79%) and stem (95%) lodging rate; therefore, RF2 cultivation method might be an appropriate water saving approach in semi-arid regions.

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.

Cultivation modes and deficit irrigation strategies to improve 13C carbon isotope, photosynthesis, and winter wheat productivity in semi-arid regions.

Determining the effect of ridge-furrow cultivation mode on 13C carbon isotope discrimination, photosynthetic capacity, and leaf gas exchange characteristics of winter wheat leaves will help to increase wheat production. To verify these effects of cultivation modes with deficit irrigation will provide scientific basis for determining water-saving strategy. Therefore, a mobile rainproof shelter was used to explore the potential benefit of two cultivation modes: (1) the ridge-furrow (RF) precipitation system and (2) traditional flat planting (TF) with two deficit irrigation levels (150, 75mm) and three precipitation levels (275mm, 200mm, 125mm) were tested in this study. Plastic film mulching on ridges had significant effects on rainwater collection and improved soil water retention. Analysis of the light-response curve showed that RF2150 treatment significantly increased flag leaf net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate (Tr), leaf WUE, and total contents of chlorophyll ab of wheat at flowering stage than that of TF planting. The RF system significantly increases maximum net photosynthetic rate (Pnmax) (16.2%), light saturation points (LSP) (6.7%), and Pn under CO2-response curves compared to the TF cultivation across the two irrigation and three simulated rainfall levels. The RF system significantly increased Δ13C (0.7%) and caused a notable increase in the intercellular to ambient CO2 concentration ratio (7.6%), dry matter translocation (54.9%), and grain yield plant-1 (19%) compared to the TF planting. Furthermore, Δ13C was significantly positively correlated with Pn, Gs, Ci/Ca, Ci, Tr, Pnmax, LSP, and grain yield. This study suggested that the RF2150 treatment was the best water-saving technique because it increased soil water content, Δ13C, biomass, grain yield, and leaf WUE.

半干旱区垄沟集雨系统点尺度土壤水分动态随机模拟

半干旱区垄沟集雨系统点尺度土壤水分动态随机模拟

Plastic film mulching combined with nutrient management to improve water use efficiency, production of rain-fed maize and economic returns in semi-arid regions

To examine the combined effects of planting models with nutrient management strategies on grain filling rates, productivity, soil water storage, water-use efficiency and economic benefit of rain-fed corn, there for a field research was carried out during 2015–2016 in a semi-arid region of China. Three planting models were tested: ridge furrow system with plastic mulching (M1), furrow planting with soil crust ridges (M2), and flat planting without plastic mulching (M3); in combination with four nitrogen levels: 0 kg ha–1 (N0); 100 kg ha–1 (N1); 200 kg ha–1 (N2), and 300 kg ha–1 (N3). We found that M1 planting model with higher 300 kg-1 N ha-1 could significantly increase soil water availability at different growth stages, as a result significantly increased WUE (56.6%), RUE (71.2%), ET (8.8%), soil water storage, biomass (35.5%), and grain yield (70.8%) of rain-fed maize than that of M3N0 treatment. Increasing the nitrogen level as a result significantly increased the economic benefit, yields and yield components of rain-fed maize under different planting models, but AEN shows a significantly decreasing trend. The M1N3 treatment significantly promoted the LAI and grains filling of the basal, middle and upper seeds than that of M2 and M3 cultivation models with the highest nitrogen level. The M1N3 treatment obtained the highest (12,775 CNY ha-1) net profit, improved the SWS throughout the grain-filling duration, which resulted in higher productivity. Thus, M1N3 treatment can be used to improving productivity, economic benefit, and water use in semi-arid areas.

Fate and transport of urea-N in a rain-fed ridge-furrow crop system with plastic mulch

A better understanding of the fate and transport of fertilizer nitrogen (N) is critical to maximize crop yields and minimize negative environmental impacts. Plastic film mulching is widely used in drylands to increase soil water use efficiency and crop yields, but the effects on fertilizer N use efficiency need to be evaluated. A field experiment with 15N-urea (260 kg N ha−1) was conducted to determine the fate and transport of fertilizer N in a ridge-furrow system with plastic film mulched ridge (Plastic), compared with a flat system without mulching (Open). In the Plastic, the 15N-urea was applied to the ridge only (Plastic-Ridge), or to the furrow only (Plastic-Furrow). Maize grain yield and net economic benefit for Plastic were significantly higher (by 9.7 and 8.5%, respectively) than those for Open. Total plant 15N uptake was 72.5% greater in Plastic compared with Open, and 15N was allocated mostly to the grain. Losses of the applied urea-N were 54.5% lower in Plastic and much more residual 15N was recovered in 0–120 cm soil compared with Open (42.7 and 26.8% of applied 15N, respectively). Lateral N movements from furrow to ridge and from ridge to furrow were observed and attributed to lateral movement of soil water due to microtopography of ridges and furrows and uneven soil water and heat conditions under mulching and plant water uptake. The ridges were the main N fertilizer source for plant uptake (96.5 and 3.5% of total N uptake in Plastic from ridge and furrow, respectively) and the furrow was the main source of N losses (78.6 and 21.4% of total N losses in Plastic from furrow and ridge, respectively). Gas emissions, especially ammonia volatilization was probably the main N loss in furrow. Thus, appropriately localized N application – into the ridges, and management strategies should be designed for Plastic to maximize N use efficiency by crops, decrease N gas losses and maintain sustainable agricultural systems in drylands.