Furrow Rainfall Harvesting Research Articles

Water footprint and production of rain-fed saffron under different planting methods with ridge plastic mulch and pre-flowering irrigation in a semi-arid region

Most of the saffron cultivation areas in Iran are irrigated and with pre-flowering irrigation being necessary to facilitate flower emergence. However, the growers face shortage of water. Post- flowering rain-fed (PFRF) saffron cultivation could be a solution, and ridge and furrow rainfall harvesting (RFRH) with plastic mulch could be used to collect runoff in the field planting areas. In this regard, the objectives of this study were to determine the effects of interaction of two different saffron planting methods (basin and furrow planting), using plastic mulch and without plastic mulch on ridge of the furrow planting, using irrigation at pre-flowering and without irrigation on saffron growth, yield, yield components, economic water productivity (EWP) and water footprint of saffron in two growing seasons with low (167 mm) and high (367 mm) seasonal rainfall in a semi-arid region. Without irrigation in pre-flowering (NPFI) produced a saffron yield reduction of 70% compared with pre-flowering irrigation (PFI). It is concluded that 90 mm of irrigation water should be applied as PFI for adequate flowering and yield. In addition, the use of the RFRH system resulted in a runoff coefficient of 0.85 and increased soil water storage (48% at low seasonal rainfall), saffron yield (51%), leaf dry matter, LDM (90%) and EWP (17%). The blue water footprint (BWF) with low rainfall (165 mm) was higher than that with abundant rainfall (367 mm), because saffron yield in the second year was lower due to the older age of saffron in field, which resulted in lower yield and consequently higher BWF. Likewise, green water footprint (GWF) was higher (4810 m3 kg−1) than those that obtained as BWF (739 m3 kg−1) due to the fact that pre-flowering irrigation is necessary for onset of flower and the regional rainfall is insufficient to initiate flowering. The effects of low seasonal precipitation (less than 200 mm) on saffron were manifested in yield and LDM reduction of 70% and 42%, respectively, compared to high seasonal precipitation, decreasing as seasonal precipitation increased. Precipitation reached around 300 mm in rain-fed with pre-flowering irrigation caused no reduction in saffron yield and LDM. Therefore, in PFRF conditions, furrow planting with ridge plastic mulch and pre-flowering irrigation is recommended. The economic water footprint of saffron under PFRF conditions with PFI was 50% of that obtained for irrigated saffron production, which is preferable in virtual water trade.

Suitable fertilization can improve maize growth and nutrient utilization in ridge-furrow rainfall harvesting cropland in semiarid area.

The ridge-furrow rainfall harvesting system (RFRH) improved the water shortages, and reasonable fertilization can promote nutrient uptake and utilization of crops, leading to better yield in semi-arid regions. This holds significant practical significance for improving fertilization strategies and reducing the application of chemical fertilizers in semi-arid areas. This field study was conducted to investigate the effects of different fertilization rates on maize growth, fertilizer use efficiency, and grain yield under the ridge-furrow rainfall harvesting system during 2013-2016 in semiarid region of China. Therefore, a four-year localization field experiment was conducted with four fertilizer treatments: RN (N 0 kg hm-2, P2O5 0 kg hm-2), RL (N 150 kg hm-2, P2O5 75 kg hm-2), RM (N 300 kg hm-2, P2O5 150 kg hm-2), and RH (N 450 kg hm-2, P2O5 225 kg hm-2). The results showed that the total dry matter accumulation of maize increased with the fertilizer application rate. The nitrogen accumulation was highest under the RM treatment after harvest, average increase by 1.41% and 22.02% (P<0.05) compared to the RH and RL, respectively, whereas the phosphorus accumulation was increased with the fertilizer application rate. The nitrogen and phosphorus use efficiency both decreased gradually with the fertilization rate increased, where the maximum efficiency was observed under the RL. With the increase of fertilizer application rate, the maize grain yield initially increased and then decreased. Under linear fitting, the grain yield, biomass yield, hundred-kernel weight, and ear-grain number all showed a parabolic trend with the increase of fertilization rate. Based on comprehensive consideration, the recommended moderate fertilization rate (N 300 kg hm-2, P2O5 150 kg hm-2) is suitable for the ridge furrow rainfall harvesting system in semiarid region, and the fertilization rate can be appropriately reduced according to the rainfall.

Planting models and deficit irrigation strategies to improve radiation use efficiency, dry matter translocation and winter wheat productivity under semi-arid regions

The dry-land farming system of China relies on plastic film mulching and natural rainfall to mitigate damage caused by drought. However, the applications of deficit irrigation modes combined with the planting models can significantly increase production of wheat, dry matter translocation and radiation use efficiency (RUE) remains unidentified. Thus, in 2016–2018, we conducted field trials that implemented four deficit irrigation modes (IJF: irrigation at jointing and flowering stages; IF: irrigation at flowering stage; IJ: irrigation at jointing stage; NI: no irrigation) under two cultivation patterns (ridge furrow rainfall harvesting system (RF); traditional flat cultivation (TF)). The results indicated that the effects of RF system with deficit irrigation (IJF: 250 mm) could significantly increase the soil moisture, and thus enhanced LAI, In value, IPAR, RUE, and PAR capture ratio than that of TF-NI planting. This is due to decreased canopy light transmittance (LT), reflection and penetration ratio of PAR, as a result considerable improve the biomass translocation and grain yield. Owing to the very low soil water content after the seed-filling, the LAI, IPAR, and In value decreased during the seed-filling under water stress, ultimately affecting the dry matter translocation efficiency. While the IJF and IF treatments provided water for reproductive growth stage, therefore, the production of wheat and RUE were significantly maximum compared with IJ and NI irrigation mode. Under the RF system with IJF, IF, and IJ treatments the grain yield increased by 81.2%, 56.8%, 45.6% and 17.2%, then that of TF-NI treatment, respectively. The highest RUE (1.93 g MJ−1), dry-matter translocation (154.2%) and seed yield (81.2%) were obtained in the RF-IJF treatment compared with TF-NI. Therefore, the RF-IJF treatment significantly improved the earlier development and rapid plant growth, which is a suitable planting model for increasing soil moisture, LAI, RUE, DMT, and winter wheat production.

Ridge–furrow rainfall harvesting system helps to improve stability, benefits and precipitation utilization efficiency of maize production in Loess Plateau region of China

The ridge–furrow rainfall harvesting (RFRH) system is considered an effective strategy for improving crop productivity and it has been adopted increasingly in the arid and semiarid rainfed agricultural areas of China. However, how RFRH performs at improving the crop productivity and the economic benefits of long-term implementation are not known in different counties and conditions in the Loess Plateau region. Therefore, RFRH and traditional planting method (CK) experiments were carried out by us under five different hydrothermal conditions in the Loess Plateau for many years. The denitrification–decomposition (DNDC) model was corrected and verified by field test data. Then, the performance of RFRH and CK in time (from 1990 to 2019, three test points) and space (387 counties, 112,000 km−2 grain crop planting area) was simulated. The results showed that from 1990 to 2019, the maize yield was 9200–11,395 kg ha–1 under RFRH and 1433–11,326 kg ha–1 under CK. The interannual variation in the maize yield was small under RFRH and it significantly improved the maize yield in dry years (87.0% higher than CK). In addition, RFRH effectively stabilized and improved the maize biomass (increased by 26.9%), harvest index (increased by 24.3%), and economic benefits (increased by 63.4%). In the whole Loess Plateau region, compared with CK, the average grain yield under RFRH increased by 86% and the average net income increased by 133%. The capacity of RFRH to increase the economic benefits in the Loess Plateau regions followed the order of: northwest region > northeast region > southwest region > southeast region. RFRH can improve and stabilize the maize yield, but also enhance the economic benefits of maize production in this region. Therefore, RFRH can be used as an important technique for coping with years when different amounts of precipitation occur in the Loess Plateau region, but especially in the northwest where the precipitation is limited.

Ridge and furrow rainfall harvesting can significantly reduce N2O emissions from spring maize fields in semiarid regions of China

The ridge and furrow rainfall harvesting (RFRH) system is an effective method for enhancing the rainfall water use efficiency and crop yield. Determining how the fertilization rate affects soil nitrous oxide (N2O) emissions under the RFRH system has important practical significance for improving fertilization strategies and evaluating the environmental effects of the RFRH system. Therefore, we conducted a three-year field experiment in the Loess Plateau, China, to compare the RFRH system with traditional flat planting (T) at four different fertilizer rates (no fertilizer, N:P2O5 at 150:75 kg ha–1, N:P2O5 at 300:150 kg ha–1, and N:P2O5 at 450:225 kg ha–1). Under the same fertilization level, the soil water content (SWC) and dry matter were higher under RFRH compared with T, and the nitrate nitrogen (NO3−-N) content and N2O emissions were reduced. In the two planting models, SWC and NO3−-N of each treatment and its corresponding N2O emission flux were significantly positively correlated. Under the same planting model, SWC decreased but NO3−-N and the N2O emission increased with increasing fertilization rate. SWC was the key variable affecting the N2O emission flux in the RFRH system. In addition, the grain yield under RFRH increased by 2.2–28.0%, whereas the global warming potential (GWP) and greenhouse gas intensity (GHGI) decreased by 1.0–16.1% and 13.0–56.8%, respectively, compared with T. The grain yield and GHGI had quadratic relationships with the fertilization rate. Moreover, GWP increased in a linear manner with the fertilizer rate. These findings suggest that the RFRH system is an effective tillage measure for reducing N2O emissions. When the N:P2O5 fertilization rate was 200:100 to 307:154 kg ha−1, the RFRH system could maintain a higher grain yield and reduce the N2O emissions.

Variations in soil fungal communities after continuous fertiliser treatment under the ridge and furrow rainfall harvesting system in a semiarid region of China

The ridge and furrow rainfall harvesting (RFRH) system enhances the rainfall use efficiency and crop yield in rain-fed areas of north-western China. In this study, we determined the effects of RFRH on the soil fungal community composition and diversity in a 5-year fertilisation experiment (N:P fertiliser rates of 0:0, 150:75, 300:150, and 450:225 kg ha–1 year–1) in the dryland farming area of the Loess Plateau. Excessive fertiliser application reduced the crop productivity and a moderate rate of 300:150 kg ha–1 year–1) produced the highest maize yield. The available phosphorus (AP), organic carbon, nitrate-nitrogen (NO3-N) and total nitrogen contents increased with the fertiliser rate, whereas soil water content decreased. The relative abundances of Ascomycota, Fusarium and Zygomycota increased (P &amp;lt; 0.05) with the fertiliser application rate, whereas those of Basidiomycota and Glomeromycota decreased (P &amp;lt; 0.05). The fungal diversity (Shannon–Wiener index: P = 0.016) and composition (unweighted UniFrac: P = 0.024) were significantly affected by fertilisation. The NO3-N and AP were the main factors that affected fungal composition and diversity. Thus, fertilisation changed the fungal community composition and diversity, and a higher fertiliser rate negatively affected nutrient cycling and the stability of the soil ecosystem under RFRH.

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.

Cultivation techniques and nutrient management strategies to improve productivity of rain-fed maize in semi-arid regions

A field study was conducted during 2015–16 in a semi-arid area of the Loess Plateau China to clarify the interactive effects of cultivation techniques with different N and P fertilization levels on the maize growth, yield, evapotranspiration, and water use efficiency. Two planting models were tested: conventional flat planting (M1), and ridge furrow (RF) rainfall harvesting planting model (M2); with four N:P fertilizer rates: 0:0 kg ha–1 (F0); 100:50 kg ha–1 (F1); 200:100 kg ha–1 (F2), and 300:150 kg ha–1 (F3). The RF system increased the soil water storage (SWS), where the SWS exhibited a decreasing trend as the fertilization rate increased under both cultivation models. At 120 days after planting (DAP) the mean, SWS at the depth of 0–200 cm under the M1F0, M1F3, M2F0 and M2F3 treatments was 376.5 mm, 345.7 mm, 350.6 mm and 325.4 mm. The mean WUE over 2 years increased significantly (P < 0.05) with M2F3, M2F2, M1F3, M1F2, M2F1, and M1F1 by 53%, 37.7%, 34.7%, 31.9%, 21.6%, and 19.0% compared with M1F0 and M2F0 treatments. Maize responded positively to fertilizer, and F2 was the economical fertilizer input rate, where the leaf area, dry matter accumulation and grain yield increased significantly with increasing fertilization rate up to the economically optimal rate (F2). Beyond the optimal rate, these quantities increased slightly as did the yields and economic returns. Agronomic efficiency steadily decreased with fertilization rate beyond the F1 level. The economic benefit was 54% greater under M2F2 treatment, which also obtained significantly higher grain yield, WUE and agronomic efficiency than that of M2F0 treatment. Thus, we recommend the M2F2 planting model for high productivity and efficient maize production in semi-arid regions.

Tillage and deficit irrigation strategies to improve winter wheat production through regulating root development under simulated rainfall conditions

Knowledge of rooting systems and soil water status across rooting zones is important for stabilizing agricultural productivity in the semi-arid regions of China. In the present study, a mobile rainproof shelter trial was performed to find out the effects of cultivation mode on the temporal and spatial root growth distribution, soil water content, root respiration rate, and grain yield during 2015–2016 and 2016–2017 growing seasons. The two cultivation modes were: (1) the ridge furrow (RF) rainfall harvesting technique; and (2) traditional flat planting (TF). In addition, three simulated rainfall (1: 275, 2: 200, 3: 125 mm) and two deficit irrigation (150, 75 mm) levels were used. Our results showed that different cultivation modes with simulated precipitation levels significantly improved moisture content for wheat growth, improved root growth, and provided favourable conditions for higher wheat production. The RF150 treatment with 200 mm rainfall significantly increased morphology of the wheat rooting system, especially in the top 40 cm soil layer compared with TF cultivation. The RF150 treatment significantly increased root dry weight (47%), root tissue density (6.7%), root fineness (4.8%), root length ratio (20.3%), root mass ratio (27.3%), and grain yield (18.9%) of wheat at 200 mm rainfall than that of TF2150 treatment. Root weight density, root length density, root surface area density, and root diameter were significantly higher under RF150 treatment with 200 mm and 275 mm precipitation in the 40 cm soil layer and reached maximum values at the flowering stage. The root dry weight, root respiration rate, and grain yield were significantly improved under RF2150 treatment, but there were no significant differences when the rainwater increased from 200 to 275 mm under both cultivation modes. Therefore, we suggested that the RF2150 treatment is a suitable water saving strategy to improve temporal and spatial root growth distribution, resulting in higher grain yield in a dry-land farming system.

Effects of different fertilizer strategies on soil water utilization and maize yield in the ridge and furrow rainfall harvesting system in semiarid regions of China

Shortages of water resources and low soil fertility are two key factors that limit crop production in semiarid areas. The ridge and furrow rainfall harvesting (RFRH) system is an effective method for enhancing the efficiency of rainfall water use and fertility. In this study, we conducted a field experiment over five years (2012–2016) to determine the effects of different fertilizer application rates on the soil water consumption properties, water use efficiency, and maize yield under RFRH. We found that the evapotranspiration (ET), maize dry matter (DM), water consumption strength (CD), and soil water use rate (SP) increased with the fertilizer application rate. Compared with the no fertilizer treatment (RCK), ET, DM, CD, and SP increased significantly by 7.2%, 38.3%, 16.4%, and 37.6% under high fertilizer (RH) treatment, respectively, by 6.7%, 35.8%, 18.0%, and 39.1% with medium fertilizer (RM) treatment, and by 5.5%, 31.1%, 16.1%, and 32.6% with low fertilizer (RL) treatment. RM achieved the highest average yield of 11.3 t ha–1 and the lowest coefficient of variation at 12.9%. The yield, DM, and water use efficiency did not differ significantly between RH and RM. Regression analysis showed that the highest yield could be obtained by applying nitrogen at 265.0 kg ha–1 combined with P2O5 at 132.5 kg ha–1. The yield and water use efficiency were significantly higher under RL compared with RH and RM in wet year. However, in both normal and drought years, the grain yield and water use efficiency was significantly higher under RM. These results indicate that the RFRH system can promote crop use of fertilizers by regulating soil moisture. The best fertilization strategy for planting maize with RFRH system was 265.0 kg ha–1 of pure nitrogen combined with 132.5 kg ha–1 of P2O5 in the semiarid area of the Loess Plateau, in China.

Interactive effects of plastic film mulching with supplemental irrigation on winter wheat photosynthesis, chlorophyll fluorescence and yield under simulated precipitation conditions

Water shortages continuously threaten agricultural productivity in semi-arid regions. Efficient water-saving management practices urgently need to be developed. In the present study, a mobile rain shelter was used with two cultivation modes: (1) the ridge furrow (R) rainfall harvesting system; and (2) traditional flat planting (F). In addition, two supplemental irrigation levels (150, 75 mm) and three precipitation levels (1: 275, 2: 200, 3: 125 mm) were included in this study. We demonstrated that the R system with 150 mm supplemental irrigation and 200 mm simulated rainfall can significantly improve winter wheat net photosynthesis rate (Pn), electron transport rate (ETR), effective quantum yield of PS II (ΦpsII), maximum quantum efficiency of PSII (Fv/Fm), variable fluorescence (Fv), energy transformation potential of PSII (Fv/Fo), and leaf photosynthetic performance index of PSⅡ (Fv/Fmʹ), at the jointing, flowering, and later stage of grain filling. These improvements were due to significantly increased soil moisture content, total chlorophyll ab contents (13.1%), and chlorophyll stability index (88.3%) of flag leaves, and decreased (32.7%) evapotranspiration (ET) at field scales and soil temperature, all of which increased the grain yield (18.9%) and water use efficiency (WUE, 75.8%) compared with traditional flat planting. The chlorophyll fluorescence parameters of winter wheat were significantly positively correlated with the Pn, total Chl, WUE, and grain yield (except ET). These results suggest that the R system with 150 mm supplemental irrigation and 200 mm simulated rainfall was the best cultivation practice for improving photosynthesis, chlorophyll fluorescence, WUE, and yield of winter wheat in semi-arid regions.

Effects of planting patterns and sowing densities on grain-filling, radiation use efficiency and yield of maize (Zea mays L.) in semi-arid regions

The ridge-furrow rainwater harvesting system is a valuable technique for collecting runoff water and increasing radiation use efficiency to improve crop production. Field experiments were conducted over two consecutive years (2015–16) on a loess soil in semi-arid regions of China. Three different planting densities (L: 52500 plant ha−1; M: 75000 plant ha−1; H: 97500 plant ha−1) and three different planting patterns (RF: ridge and furrow rainfall harvesting system; FM: flat planting with plastic film mulching; CP: conventional planting without plastic film) were used to measure various maize characteristics. The objectives were to enhance the water use efficiency (WUE), radiation use efficiency (RUE), and promote the grain-filling process and yields of maize. The results showed that under the same densities, there was no significant differences between the average filling rate (Gmean) and the maximum filling rate (Gmax) (P>0.05) during the normal-precipitation year (2015). However, the Gmean and Gmax in the RF and FM treatments were significantly higher than the CP treatment in dry year (2016). Under the same densities, the number of grains per row, number of kernels per ear, and kernel yield per plant of RF and FM treatments were significantly higher than those of the CP treatment. These maize yield components decreased with increased planting densities under the same planting patterns. Compared to the CP treatment, the average annual grain yield under the RF and FM treatments increased by 33.4% and 30.0%, respectively. Compared to the CP treatment, the average annual RUE in the RF and FM treatments increased by 12.4% and 11.5% before silking and increased 17.7% and 14.7% after silking, respectively. Under the RF system with a middle planting density (M-RF) promoted grain-filling rate, grain yield, yield components, WUE, and RUE. Therefore, we concluded that M-RF model is the most suitable for increases maize yield and RUE in the semi-arid regions of China.

Deficit irrigation and planting patterns strategies to improve maize yield and water productivity at different plant densities in semi-arid regions

Field research was done in two consecutive years to optimize deficit irrigation under different crop densities (low, medium, and high) using the ridge and furrow rainfall harvesting (RFRH) system. We demonstrate that applying deficit irrigation (375 m3 ha−1) at the flowering stage of maize grown at medium density (M: 75000 plant ha−1) under the RFRH system (MIF) can improve soil water storage (0–200 cm) at the bell, filling and flowering stages. MIF increased biomass by 10% and grain yield by 21%, thereby achieving a 17% increase in water use efficiency (WUE) and a 22% increase in precipitation use efficiency (PUE) compared with conventional flat planting (CKM). MIF also improved irrigation water use efficiency (IWUE) (9%) and irrigation water productivity (IWP) (46%) compared with no-irrigation under the RFRH system (MI0). We observed that applying deficit irrigation (750 m3 ha−1) at the bell and flowering stage (IBF) had positive effects on dry matter, leaf area, and evapotranspiration, but there were no significant increases in IWUE, IWP, WUE, biomass and grain yield compared with maize grown under IF at low, medium and high plant densities. The average net profit over the two years was 34% higher for MIF compared with the CKM treatment.

Strategies for reducing the fertilizer application rate in the ridge and furrow rainfall harvesting system in semiarid regions

The ridge and furrow rainwater harvesting (RFRH) system is a promising water-saving planting technique for dryland farming, but we lack a full understanding of the effects of different fertilizer rates (N:P) on plant nutrient uptake and nutrient use efficiency (NuUE) in foxtail millet using this planting method, as well as the available nutrient residues in the soil. We conducted field studies (Loess Plateau, China) comparing RFRH planting (R) and traditional flat planting (T) at four different fertilizer rates to determine suitable fertilizer application rates for R during 2013–2015. Compared with T, R improved the soil moisture and the utilization of rainwater and fertilizer, thereby enhancing the grain yield, water use efficiency (WUE), grain nutrient uptake, and NUE in a dry year, but with no improvements in a rainy year. The grain yield and WUE exhibited parabolic increasing trends as the fertilizer application rate increased over three years, but no significant increase was found when the fertilizer rate exceeded 189:96 kg N:P ha−1 under R, which significantly reduced the NuUE and might waste nutrients. Therefore, we recommend R combined with 189:96 kg N:P ha−1 as a promising planting strategy for foxtail millet in semiarid areas.

Nutrient and tillage strategies to increase grain yield and water use efficiency in semi-arid areas

Water and fertilizer are major factors that influence crop productivity in dryland farming. The ridge and furrow rainfall harvesting (RFRH) system is known to be an effective planting method for improving rainwater utilization, but suitable fertilizer application rates for foxtail millet under RFRH planting have not yet been determined. In 2014 and 2015, we examined the effects of four fertilizer application rates (F0, F1, F2, and F3) under RFRH planting (RFRHP) and traditional flat planting (TFP) on the soil water content (SWC), evapotranspiration (ET), plant growth, grain yield, and resource use efficiency for foxtail millet. We found that RFRHP improved the SWC, where the SWC exhibited a decreasing trend as the fertilizer rate increased, but generally there was no significant difference among F1, F2 and F3 under both planting patterns. Compared with TFP, RFRHP produced a slightly higher maximum leaf area and dry matter accumulation, although the differences were not significant, while total ET was reduced and there were general improvements in the harvest index, grain yield, water use efficiency (WUE), agronomic efficiency, and net economic benefit. Foxtail millet responded positively to fertilizer, and F2 was the economical fertilizer input rate, where the leaf area, dry matter accumulation, and grain yield were increased slightly with no significant difference when the fertilizer rate was increased beyond F2, while agronomic efficiency was significantly decreased. The highest economic net benefit was achieved by RFRHP combined with F2, which also obtained significantly higher grain yield, WUE and agronomic efficiency compared with TFP. Thus, we recommend the RFRH system with F2 (186:96kgN:Pha−1) for high productivity and efficient foxtail millet production in semi-arid areas.

Effects of ridge and furrow rainwater harvesting system combined with irrigation on improving water use efficiency of maize (Zea mays L.) in semi-humid area of China

The ridge and furrow rainfall harvesting (RFRH) system collecting runoff by the plastic mulched ridges is a useful method to improve crop productivity in northwest China. We performed a field study where the RFRH system was combined with irrigation (RI) to reduce water irrigation use and to increase the crop water use efficiency (WUE) in a semi-humid climate. The amount of irrigation using RI was reduced by half compared with traditional furrow irrigation (FI) and border irrigation (BI) due to its rainwater harvesting effects. Our results showed that the RI treatment effectively alleviated drought stress during key periods of crop growth. At the jointing stage, the soil water storage in the 0–200cm soil layer was increased by 2.82–8.02% and 2.25–8.40% compared with FI and BI, respectively, and the soil water consumption by maize below 60cm was significantly decreased at the tasselling stage. With RI, the harvest biomass, grain yield, and WUE were significantly increased by 14.59–19.93%, 5.33–7.01%, and 12.21–18.01% compared with FI, respectively, and compared with BI, these values were significantly increased by 24.48–27.25%, 8.83–11.23%, and 14.99–22.91%, respectively. The irrigation amount was reduced by 1500m3hm−2, and the irrigation WUE with RI was 2.1 and 2.2 times higher than that using FI and BI. The irrigation water productivity was improved by 1.71 and 5.70 times compared with FI and BI, respectively in 2011. These results suggest that combining the RFRH system with irrigation is suitable for reducing irrigation water use by enhancing the efficient utilization of local rainfall, which could have very important applications in irrigated fields in semi-humid or semi-arid areas.

Effects of Rainfall Harvesting and Mulching on Corn Yield and Water Use in the Corn Belt of Northeast China

The Corn Belt of Northeast China is the most important corn production area in China, accounting for 30% of the total corn production. However, seasonal drought conditions limit local corn production. Field experiments were conducted in 2011 and 2012 in Lishu county (Jilin Province, China) to study the effects of ridge and furrow rainfall harvesting and mulching on corn yields, evapotranspiration (ET), and water use efficiency (WUE) in black and aeolian sandy soils. The treatments included flat planting bed (FB), plastic‐mulched ridges with bare furrows (RFB), and plastic‐mulched ridges with straw‐mulched furrows (RFM). For both soil types, the RFB and RFM treatments improved soil water conditions in the root zone. However, adding straw mulch did not consistently improve soil water content. In the black soil, the RFB treatment did not affect crop yield but increased WUE by 13% relative to the FB treatment in 2011. Furthermore, yield and WUE decreased by 30 and 24%, respectively, in 2012. In the aeolian sandy soil, the RFB treatment increased yield and WUE by 26 and 25%, respectively, relative to the FB treatment in 2011. However, the RFB treatment had no effect on yield or WUE in 2012. For both soil types, the RFM treatment did not significantly affect yield or WUE relative to the RFB treatment during 2011 or 2012. Therefore, the RFB treatment should only be used in aeolian sandy soils to achieve higher corn yields and WUEs and not be recommended for black soils when the soil water is sufficient.

Application of Mulching Materials of Rainfall Harvesting System for Improving Soil Water and Corn Growth in Northwest of China

The ridge and furrow rainfall harvesting (RFRH) system is used for dryland crop production in northwest of China. To determine the effects of RFRH using different mulching materials on corn growth and water use efficiency (WUE), a field experiment was conducted during 2008–2010 at the Heyang Dryland Experimental Station, China. Four treatments were used in the study. Furrows received uncovered mulching in all RFRH treatments whereas ridges were mulched with plastic film (PF), biodegradable film (BF) or liquid film (LF). A conventional flat field without mulching was used as the control (CK). The results indicated that the average soil water storage at depths of 0–200 cm were 8.2 and 7.3%, respectively higher with PF and BF than with CK. However, LF improved soil water storage during the early growth stage of the crop. Compared with CK, the corn yields with PF and BF were increased by 20.4 and 19.4%, respectively, and WUE with each treatment increased by 23.3 and 21.7%, respectively. There were no significant differences in corn yield or WUE with the PF and BF treatments. The net income was the highest with PF, followed by BF, and the 3-yr average net incomes with these treatments were increased by 2 559 and 2 430 CNY ha−1, respectively, compared with CK. BF and PF had similar effects in enhancing the soil water content, crop yield and net income. Therefore, it can be concluded that biodegradable film may be a sustainable ecological alternative to plastic film for use in the RFRH system in northwest of China.

Effects of ridge and furrow rainfall harvesting system on soil hydrothermal condition and yields of Elymus sibiricus L. in arid and semiarid regions

Effects of ridge and furrow rainfall harvesting system on soil hydrothermal condition and yields of Elymus sibiricus L. in arid and semiarid regions

Effects of ridge and furrow rainfall harvesting system on Elymus sibiricus yield in Bashang agro-pastoral zone of China

A ridge-furrow rainfall harvesting system (RFRHS) was designed to increase the available soil water for Elymus sibiricus artificial grassland in order to improve and stabilize its yield in the agro-pastoral zone of Bashang region in North China. Field experiments were conducted during the growth seasons in 2008 to 2010 to evaluate the effects of the RFRH system on soil temperature, soil water content and the yield of E. sibiricus. Specifically, the following three systems were investigated: ridge width 60 cm and furrow width 30 cm (MR60), ridge width 30 cm and furrow width 30 cm (MR30) and flat (CK). The results show that in regrowth periods, average daily minimum temperature of MR30 and MR60 in the furrow soil surface was 3.22 and 2.16°C, which were significantly higher than that of CK. Soil water content of MR60, was higher than that of MR30 and the latter was higher than that of CK in most of the experimental periods. Due to the improved hydrothermal condition, the three year average of annual yields of MR60 and MR30 was 3.14 and 2.77 t ha -1 , which was significantly higher and increased by 99