Greenhouse Vegetable Production Research Articles

The potential importance of soil denitrification as a major N loss pathway in intensive greenhouse vegetable production systems

BackgroundAbout 30 % of vegetables in China are produced in intensively managed greenhouses comprising flood irrigation and extreme rates of nitrogen fertilizers. Little is known about denitrification N losses.MethodsSoil denitrification rates were measured by the acetylene inhibition technique applied to anaerobically incubated soil samples. Four different greenhouse management systems were differentiated: Conventional flood irrigation and over-fertilization (CIF, 800 kg N ha−1, 460 mm); CIF plus straw incorporation (CIF+S, 889 kg N ha−1, 460 mm); Drip fertigation with reduced fertilizer application rates (DIF, 314 kg N ha−1, 190 mm); DIF plus straw incorporation (DIF+S, 403 kg N ha−1, 190 mm). Soil denitrification was measured on nine sampling dates during the growing season (Feb 2019-May 2019) for the top-/ subsoil (0 – 20/ 20- 40 cm) and on three sampling dates for deep soils (40-60/ 80-100 cm). Data was used to constrain N-input-output balances of the different vegetable production systems.ResultsRates of denitrification were at least one magnitude higher in topsoil than in sub- and deep soils. Total seasonal denitrification N losses for the 0 – 40 cm soil layer ranged from 76 (DIF) to 422 kg N ha−1 (CIF+S). Straw addition stimulated soil denitrification in top- and subsoil, but not in deep soil layers. Integrating our denitrification data (0-100 cm) with additional data on N leaching, N2O emissions, plant N uptake, and NH3 volatilization showed, that on average 50 % of added N fertilizers are lost due to denitrification.ConclusionsDenitrification is likely the dominant environmental N loss pathway in greenhouse vegetable production systems. Reducing irrigation and fertilizer application rates while incorporating straw in soils allows the reduction of accumulated nitrate.

Influence of root feeding fertilizers on yield and quality of winter wheat grain in conditions of the central zone of Orenburg region

Agriculture continues to move forward confidently. Before our eyes, the agrarian industry is reviving, becoming stronger, taking a strong position at the forefront of the Russian economy. The most important achievement of 2017 was a record grain harvest of 130 million tons. This result was achieved not only by increasing the cultivated areas, which increased by 620 thousand hectares in 2017, but also thanks to the record yield, which amounted to 28 kg / ha, which is 80% higher than in 2000. The maximum harvest in the history of new and Soviet Russia, which will ensure our country a strong leadership in the world wheat market. Russian agriculture remains a driver of the country’s economic development. For the second year in a row, we get a record harvest of not only grain, but also sugar beets and sunflowers, the production of soybeans, rapeseed and greenhouse vegetables is growing. In the new season, grain exports will reach 45 million tons, including more than 35 million tons of wheat. Russia is expanding the geography of its presence, having mastered new directions for the supply of agricultural products. At the end of 10 months of 2017, grain exports increased by 22% compared to the same period in 2016 and amounted to 32 million tons. During the same time, the export of Russian wheat exceeded 24 million tons, which is 23% more than a year earlier. … In Russia, over 17 years, the volume of grain production increased 2 times, sugar beet and sunflower - 2-3 times, soybeans and rapeseed - 10, greenhouse vegetables - 1.8, poultry meat - 6, pork - 2. Fish - 2 times. Greenhouse vegetable growing and horticulture are developing intensively. Progress is being made in the development of animal husbandry and aquaculture. The dairy industry is undergoing a significant transformation, and production volumes on farms are growing. These are new growth points for the agro-industrial complex. Thanks to the achievements of domestic scientists, grain production of agricultural crops can be increased due to many factors. One of the factors is foliar dressing with liquid micro- and macro-fertilizers. Therefore, we studied various combinations of liquid micro-, macrofertilizers, as well as the bio-logical product Albit, in order to identify the best option and recommend it for produc-tion.

Incorporating in vitro bioaccessibility into human health risk assessment of heavy metals and metalloid (As) in soil and pak choi (Brassica chinensis L.) from greenhouse vegetable production fields in a megacity in Northwest China

The rapid development of greenhouse vegetable production (GVP) in densely populated areas may cause the heavy metal/metalloid accumulation in soil and pose a threat to human health. In this study, 180 pairs of topsoil and pak choi (Brassica chinensis L.) samples were collected from GVP fields in Xi’an city in Northwest China to analyze health risks of Cd, Cr, Pb, and As in soil and pak choi combining in vitro bioaccessibility investigation. The results showed that Cd and Cr were common pollutants in both soil and pak choi. In the soil–pak choi system, the indexes of non-carcinogenic and carcinogenic risk for adults and children were 1.53, 2.68, and 1.37 × 10−4, 8.14 × 10−5, respectively, thereby indicating the presence of heavy metal/metalloid health risks for both groups. Based on the results, procedures to mitigate heavy metal/metalloid contamination risks should be discussed more during the development of GVP in the largest city in Northwest China.

Long-term organic substitution management affects soil phosphorus speciation and reduces leaching in greenhouse vegetable production

Excessive phosphorus (P) fertilizer and manure application is widespread in greenhouse vegetable production, causing P accumulation and groundwater pollution. The partial substitution of chemical fertilizer with organic amendments may effectively address this problem; however, little is known about P speciation and transformation at the molecular scale. Here, we combined P K-edge X-ray absorption near-edge structure, 31P nuclear magnetic resonance spectroscopy, and chemical extraction to characterize P speciation and assess P leaching in a 10-year field experiment including chemical fertilizer (4CN) and replacement of half the chemical N fertilizer with manure (2CN+2 MN), straw (2CN+2SN), or combined manure and straw (2CN+1 MN+1SN) treatments. Compared to the 4CN treatment, organic substitution treatments resulted in 10.0–16.3% lower P accumulation and 57.3–102% higher organic P. Newberyite was detected in the organic substitution treatments, making up 6.9–13.0% of the total P, and the hydroxyapatite proportion was 7.3–15.6% lower than that in the 4CN treatment. Moreover, 2CN+2 MN treatment increased the orthophosphate diester content and labile P (Resin-P and NaHCO3–P) proportion, and 2CN+2SN treatment increased the orthophosphate monoester content and moderately labile P (NaOH–P) proportion. The 2CN+1 MN+1SN treatment exhibited the advantages of both manure and straw application. Partial least squares path modeling revealed that labile P was affected mainly by manure application and pH, and moderately labile P was influenced mainly by straw application and alkaline phosphomonoesterase activity. Compared with the 4CN treatment, the organic substitution treatments significantly decreased the total P leaching losses by 21.3–48.8%. Our results provide new insights into soil P transformation in response to different organic amendments. Combined manure, straw, and chemical fertilizer application (2CN+1 MN+1SN treatment) was a more effective practice for developing sustainable P management practices by comprehensively considering soil P transformation, vegetable yields, and environmental losses.

Results of studying green crops of the Apiaceae family as genetic resources for vertical farming using natural immunomodulators

Relevance. New technologies Plenty-type in greenhouse vegetable production is wide spread in some countries of Europe, America, South-East Asia and support with main investors of these countries. Project “Vertical farming” was started in FSBSI “Federal Scientific Vegetable Center” at 2010. The goal of our study is the results of the testing plants Apiaceae family at multy circle hydroponic installation using the natural regulators from glycosides class.Materials and methods. Objects of study: plants Apiaceae family – Coriandrum sativum L. (variety Jubilar), Anethum graveolens L. (variety Rusich), Apium graveolens L. (variety Aeliksir); flavonoid glycoside linarozid from plants Linaria vulgaris Mill. L., steroid glycoside moldstim from seeds Capsicum annuum L.. Methods of study: seed treatment with 0,001% water solutions of glycosides, cultivation of plants Apiaceae family at the multi circle hydroponic construction.Results. First experiment by cultivation of plants Apiaceae family at multi circle hydroponic construction was successful and show, that plants Apiaceae family can cultivate at vertical installations Plenty-type. Reaction on the seed treatment with water solutions of glycosides is depended on the species of plants. Seed treatment with glycosides increased height of plants and weight of leaves of Coriandrum sativum L. Anethum graveolens L. increased germination of seeds after seed treatment with water solution of linarozide. Apium graveolens L. increased germination of seeds, height of plants and weight of leaves after seed treatment with water solutions of glycosides. But water solution of moldstim was more effective in 2020, and water solution of linarozide was more effective in 2021.

Turfgrass intercropping prevents non-point source pollution in sweet pepper production

Greenhouse vegetable production is one of the major non-point source (NPS) pollution due to its high fertilizer input and low nutrient use efficiency. Excessive salt and nutrient accumulation in the topsoil is responsible for the NPS pollution in greenhouse vegetable production. This study was designed to investigate the effects of turfgrass intercropping on NPS pollution in greenhouse sweet pepper production. The results showed that the pollution discharges via both surface runoff and leaching were significantly reduced by turfgrass intercropping. The reduction of pollution was associated with the capacity of turfgrass species in the absorption and accumulation of salts and nitrate. Paspalum vaginatum with preferential accumulations of nitrate and salts performed best results in the alleviation of soil salinity and NPS pollution. Paspalum vaginatum-intercropping decreased 51.2% of nitrate and 23.9% of electrical conductivity in the soil, 71.8% of total nitrogen, 54.9% of ammonia-nitrogen, 67.0% of nitrate-nitrogen, 68.8% of total phosphorus, 68.2% of phosphates, and 73.2% of potassium in the surface runoff, and 64.1% of total nitrogen, 53.4% of ammonia-nitrogen, 67.0% of nitrate-nitrogen, 44.3% of total phosphorus, 54.8% of phosphates, and 32.9% of potassium in the leachate. These results indicated that Paspalum vaginatum-intercropping could be a clean and sustainable solution to prevent NPS pollution in greenhouse vegetable production.

Entomoponics: combining insect rearing and greenhouse vegetable production – a case study with Tenebrio molitor and high-wire cucumber cultivation

Insect production is generally a monoculture where insects are kept in an enclosed environment with a stable climate to maximise production. To maintain these conditions air treatment is necessary, which results in high operational costs. Combining insect rearing with hydroponic greenhouse cultivation (HGC) of fruit vegetables might offer an opportunity for cost reduction. Fruit vegetables generally require more elevated air temperature, while leaving enough space under the substrate supporting gutters to allow insect rearing. In this study the feasibility of combining both production systems was evaluated with mealworms (Tenebrio molitor) and cucumber HGC serving as model species. The influence of the greenhouse climate was assessed by rearing mealworms simultaneous at two locations (a climate room and a cucumber HGC). Furthermore, pruning waste and aesthetically declined fruits could serve as a feed for insects. This was tested by comparing 4 different wet feeds (whole and mashed cucumber pruning, tomatoes and agar-agar). Larval growth was monitored and at harvest the mealworm yield was compared among treatments. Mealworm growth in the greenhouse was on average 8.1% slower than growth in a climate room even though the average ambient temperature in the greenhouse was lower and more variable (22.1±3.30 °C standard deviation compared to 27.0±0.34 °C). Moreover, the results showed that the tested HGC residues can be used as wet feed given that mashed cucumber pruning gave similar results as agar-agar (control) and tomatoes even outperformed the control significantly in terms of growth. ‘Entomoponics’ is introduced as the name for the combination of insect production and HGC of vegetables as a way to create added value in unused heated space inside a greenhouse and valorise greenhouse residues.

10-Year fertilization alters soil C dynamics as indicated by amino sugar differentiation and oxidizable organic C pools in a greenhouse vegetable field of Tianjin, China

Understanding the temporal changes of soil organic C (SOC) pools and microbial residues is essential for clarifying SOC dynamics in agroecosystems; however, this information remains largely unclear in greenhouse vegetable production (GVP) systems. Here, based on information of SOC pools (i.e., oxidizable organic C pools) and microbial residue C (MRC, as indicated by amino sugars differentiation), a 10-year (2009–2019) field experiment with fertilization was conducted to evaluate how fertilization alters SOC dynamics in a GVP field in Tianjin, China. The experiment includes four treatments (equal N, P2O5, and K2O inputs): 100% chemical N (N100), 50% substitution of chemical N with manure-N (N50M50), straw-N (N50S50), and manure-N plus straw-N (N50M25S25). Results showed that the values of SOC, lability index, and C management index increased and decreased linearly with time in N50M50- and N100-amended soils, respectively, which were mainly induced by the changes in labile C fractions. Based on logistic regression models, we found that these indices in straw-amended soils (N50M25S25 and N50S50) were rapidly increased between 2009 and 2013, and then approach steady levels between 2015 and 2019. These findings suggested that we should guarantee enough C inputs to maintain the level and quality of SOC, otherwise it will cause C loss in the unique GVP soils. Besides, straw-amended treatments increased MRC contents and enlarged their contributions to SOC sequestration, whereas these indices in N100 treatment decreased linearly with the time of fertilization. In conclusion, long-term chemical application alone was not beneficial for SOC accumulation, whereas organic amendments brought several benefits for SOC sequestration in GVP soils. Our results implied that C sequestration in GVP soils is to a large extent determined by the amounts and time of fertilization.

Biostimulants decreased nitrogen leaching and NH3 volatilization but increased N2O emission from plastic-shed greenhouse vegetable soil

Biostimulant application is an effective strategy to enhance soil fertility and plant growth. However, its comprehensive impacts on nitrogen (N) uptake and reactive N (Nr) losses via leaching, ammonia (NH3) volatilization, and nitrous oxide (N2O) emission from plastic-shed greenhouse vegetable system are still little known. Therefore, a field experiment was conducted with cauliflower-tomato growth rotation (from September 6, 2018, to July 17, 2019) receiving three biostimulants, i.e., humic acid (HA), algae extract (AE), and chitosan (CT), as well as a control without stimulant. The cumulative Nr losses over the cauliflower-tomato growth cycle via leaching, NH3 volatilization, and N2O emission were 104-175 kg N ha-1, 2.32-3.85 kg N ha-1, and 0.70-0.85 kg N ha-1, respectively. Biostimulant application significantly (P < 0.05) retarded the total N leaching by 17-44% in tomato season, while suppressed the NH3 volatilization by 18-38% in cauliflower season. Overall, AE showed the best inhibition efficiency on Nr losses by significantly (P < 0.05) decreasing total N leaching and NH3 volatilization by 36-44% and 38-52% in both vegetable seasons, compare to the control. However, all three biostimulants stimulated the N2O emission under both vegetable cycles. Interestingly, all biostimulant-added treatments promote the cauliflower and tomato yield, particularly following the HA and AE amendments, which bring local farmers approximately 4,384-10,035 yuan RMB ha-1 more income. Enhanced yield under biostimulant treatments was due to higher N uptake capacity and enhanced root morphology. In summary, biostimulants have a contrasting influence on three major Nr lost pathways in greenhouse vegetable production. We recommend that AE is the most optimal biostimulant as it increases vegetable yield and decreases total N leaching and NH3 volatilization while not dramatically increase the N2O emission.

Greenhouse gas emissions from vegetables production in China

The Chinese vegetable production system is characterized by high fertilizer inputs and environmental risks. However, the spatial patterns and mitigation potential of greenhouse gas emissions from the Chinese vegetable production systems are unknown. In this study, greenhouse gas emissions and intensity in the Chinese vegetable production systems were quantified via life cycle assessment. The weighted average greenhouse gas emissions and intensity for Chinese vegetable production were 6,244 kg CO2-eq ha−1 and 116 kg CO2-eq t−1, respectively. The total greenhouse gas emissions were 139 Mt CO2-eq. N fertilizer was the largest contributor, accounting for 78.2 % of greenhouse gas emissions. Large variations in greenhouse gas emissions and intensity were detected among the regions as well as cultivation methods. Greenhouse gas emissions in the North region were 9.7–30.0 % greater than those in the South region due to 18.2–58.2 % higher N fertilizer rate in the North region. Greenhouse gas emissions from greenhouse vegetable production were 55.4–84.1 % greater than those from open-field vegetable production because the former had 13.0–51.3 % higher N fertilizer rate and more material structure input. Greenhouse gas intensity for greenhouse vegetable production was 39.6 % higher than that for open-field vegetable production in the North region. In contrast, greenhouse gas intensity was similar for both greenhouse and open-field vegetable production in the South region. The mitigation potential for greenhouse gas emissions on a per-hectare basis was higher for the North region than that for the South region, which was attributed to a relatively greater N fertilizer reduction potential in the North region. Optimizing the N rate could reduce the total greenhouse gas emissions from the Chinese vegetable production systems by 16.7 %. This work could enable researchers and policymakers to reduce the contribution of vegetable production to global climate change.

The effects of a combined amendment on growth, cadmium adsorption by five fruit vegetables, and soil fertility in contaminated greenhouse under rotation system

Cadmium (Cd) exposure is related to a multitude of adverse health outcomes because food crops grown on Cd-polluted soil are widely consumed by the public. The present study investigates the different application techniques of a combined amendment (lime + zeolite + biochar + compost, LZBC) for soil Cd immobilization effect on growth performance, Cd uptake by the second season crops, and soil quality in greenhouse vegetable production (GVP) under a rotation system. Five fruit vegetables were cultivated as the second season crop in the same plots which have been used for pakchoi as the first season crop (with or without LZBC application). The results indicated that LZBC with the consecutive application (T3) promoted crops biomass and fruit yield the most, followed by LZBC with the second crop application (T2) and LZBC with the first crop application (T1). LZBC application showed increasing rhizosphere soil pH and improvement in soil fertility of all crops including available nitrogen, available phosphorus, available potassium, organic matter, and cation exchange capacity. LZBC had positive influences on soluble sugar, soluble protein, and vitamin C in edible parts of 5 vegetables. Cd contents in fruit, shoot, and root of eggplant, pimento, cowpea, and tomato except cucumber were reduced by adding LZBC. As for the economic performance, T3 had the highest output/input ratio in general. Overall, these results demonstrated that T3 was dramatically more effective for minimizing health risk, increasing production, and facilitating sustainable utilization of soil under the Cd-contaminated GVP system.

Phosphorus accumulation and leaching risk of greenhouse vegetable soils in Southeast China

Over-fertilization has caused significant phosphorus (P) accumulation in Chinese greenhouse vegetable production (GVP) soils. This study, for the first time, quantified profile P accumulation directly from soil P measurements, as well as subsoil P immobilization, in three alkaline coarse-textured GVP soil profiles with 5 (S5), 15 (S15), and 30 (S30) years of cultivation in Tongshan, Southeast China. For each profile, soil samples were collected at depths of 0–10 (topsoil), 10–20, 20–40, 40–60, 60–80, and 80–100 cm. Phosphorus accumulation was estimated from the difference in P contents between topsoil and parent material (60–100 cm subsoil). Phosphorus mobility was assessed from measurements of water-soluble P concentration (PSol). Finally, P sorption isotherms were produced using a batch sorption experiment and fitted using a modified Langmuir model. High total P contents of 1 980 (S5), 3 190 (S15), and 2 330 (S30) mg kg−1 were measured in the topsoils versus lower total P content of approximately 600 mg kg−1 in the 80–100 cm subsoils. Likewise, topsoil PSol values were very high, varying from 6.4 to 17.0 mg L−1. The estimated annual P accumulations in the topsoils were 397 (S5), 212 (S15), and 78 (S30) kg ha−1 year−1. Sorption isotherms demonstrated the dominance of P desorption in highly P-saturated topsoils, whereas the amount of adsorbed P increased in the 80–100 cm subsoils with slightly larger P adsorption capacity. The total P adsorption capacity of the 80–100 cm subsoils at a solution P concentration of 0.5 mg L−1 was 15.7 (S5), 8.7 (S15), and 6.5 (S30) kg ha−1, demonstrating that subsoils were unable to secure P concentrations in leaching water below 0.5 mg L−1 because of their insufficient P-binding capacity.

Partial substitution of rice husks for manure in greenhouse vegetable fields: Insight from soil carbon stock and aggregate stability

AbstractSoil aggregate stability and C stock are key factors in greenhouse vegetable production, which are influenced by the application of different organic materials. However, the responses of soil aggregate stability and C stock to organic amendment in greenhouse vegetable fields are not well understood. A 5‐year study was carried out in greenhouse vegetable fields to investigate the effect of partial substitution of rice husks for manure on soil aggregate stability, C compositions, and their relationships. Four treatments included: (a) no organic fertilization (control), (b) 30 t ha−1 chicken manure (CM), (c) 30 t ha−1 rice husks (RH), and (d) 10 t ha−1 chicken manure plus 20 t ha−1 rice husks (MR). Rice husks addition significantly increased the proportion of &gt;2 mm aggregates and mean weight diameter (MWD), while manure addition showed no difference with control. Polysaccharide and humin (HM) were increased with rice husks addition (RH and MR) compared with that in CM treatment. Polysaccharide and HM caused 86.03% variation of soil aggregate, in which polysaccharide and HM contributed 76.3 and 9.7%, respectively. The soil C stock in CM, RH, and MR treatments was increased by 146, 175, and 164% compared with control, respectively. Aliphatic‐C and amorphous Fe‐oxides (Fe‐ox) content were as higher in MR added soil than those in RH treatment. Partial substitution of rice husk for manure improved soil aggregation stability and thus enhanced C stock by suppling more polysaccharide, HM and liberated soil minerals, which was conducive to the sustainable development in greenhouse vegetable production.

Determination of the Environmental Effects of Plant Protection Products in Fighting Pests in Greenhouse Vegetable Production: Batman Province Example

This study was carried out to determine the environmental awareness levels of agricultural enterprises in the province of Batman and its districts where greenhouse production was carried out in 2020. With this purpose, and based on simple random sampling method, information was obtained from 75 producers in 15 villages, 5 randomly selected villages from three districts (Central, Besiri, Sason), using a 37 question survey method and the results have been evaluated as a percentage (%). With this study, it has been determined that the education level of the greenhouse producers is high, most of them have non agricultural income and the amount of their income is above the hunger limit. Greenhouse producers take advice from vendors and the District Directorate of Agriculture and Forestry to determine pesticide selection and pesticide dosage. They reported that the producers pay attention to important factors in the selection of pesticides like brand and active substance, they do not use the same pesticide against the same disease and pest continuously, they apply the recommended dose before the disease and pest appears, that the pesticides they use leave residues in the product, they pay attention to the waiting time between spraying and harvest, they reported that they use protective clothing and masks, do not throw empty pesticide boxes on the field or roadside, clean the spraying tool, but they said that they have use the spraying tool without calibration and applied pesticides as a mixture. However, it has been determined that they prefer cultural methods in addition to chemical methods and they are not aware of the concept of biopesticide. Farmers generally prefer chemical warfare methods to overcome plant protection problems, and mistaken pesticide applications bring many negative effects in terms of human and environmental health. Keywords: Greenhouse, Plant Protection Problems, Survey, Batman. DOI: 10.7176/JSTR/7-06-01

Assessing Aerated Vermicompost Tea Combined with Microbial Biological Control Agents for Suppression of Fusarium and Rhizoctonia.

Biological control of plant diseases is important in organic greenhouse vegetable production, where fungicide use is limited. Organic producers use microbially diverse substrates, including composts, as media for plant growth. Previous research into the impact of vermicompost on the efficacy of applied biocontrol agents is limited. An invitro assay was developed to test the efficacy of two biological control agents in a competitive microbial background. Suppression of the pathogen Fusarium oxysporum f. sp. radicis-cucumerinum by Clonostachys rosea f. catenulata (Gliocladium catenulatum strain J1446 [Prestop]) and Bacillus subtilis strain QST 713 (Rhapsody), was assessed on agar media amended with aerated vermicompost tea (ACT). Pathogen growth was reduced more by C. rosea than ACT alone, and C. rosea was equally effective when combined with ACT. In contrast, B. subtilis reduced pathogen growth less than ACT and, when combined, reduced pathogen growth no more than ACT alone. Both biocontrol agents were similarly tested with ACT against F. oxysporum f. sp. radicis-cucumerinum and Rhizoctonia solani on cucumber and radish. Additive, neutral, and antagonistic responses, depending on host, pathogen, and biocontrol agent, were observed. ACT alone provided more consistent disease suppression on cucumber compared with B. subtilis or C. rosea. In combination, disease suppression was most often better than each biocontrol alone but not better than ACT alone. ACT had antagonistic or additive interactions with C. rosea in the radish/R. solani pathosystem, depending on the experiment. The specific and general suppression of plant diseases by biological control agents in microbially rich environments is variable and warrants further study.

Comparative analysis of carbon footprint between conventional smallholder operation and innovative largescale farming of urban agriculture in Beijing, China.

The sustainable development of agriculture is one of the key issues of ensuring food security and mitigating climate change. Since innovative large-scale agriculture is gaining popularity in cities in China, where the agricultural landscape is dominated by conventional smallholder farming, it is necessary to investigate the difference in carbon emissions between conventional smallholder operation and innovative largescale agriculture. This study evaluated the carbon footprint (CF) of conventional and innovative urban agriculture in Beijing using the cradle-to-consumption Life Cycle Assessment (LCA). Two modes of greenhouse vegetable and fruit production were analyzed and compared respectively: conventional smallholder operated vegetable farms that sell in local markets versus largescale home-delivery agriculture (HDA) that deliver vegetables to consumers’ home directly, conventional smallholder operated fruit farms that sell in farm shops versus largescale pick-your-own (PYO) initiatives. Results showed that HDA and PYO can reduce CF per area in on-farm cultivation compared to smallholder operation, while may bring an increase in CF per product weight unit and the gap was wider if the supply chain was considered. This is mainly because innovative large-scale farming consumes fewer agricultural inputs (e.g., fertilizer, pesticides) and obtains lower yields than conventional smallholder operations. Plastic materials with high carbon emission, fossil energy dependence and transportation efficiency are CF hotspots of both modes and therefore can be prioritized and targeted for carbon reduction adjustment. The results of this work further advance understanding of how innovative largescale agriculture and conventional smallholder operation compare and which particular inputs and activities should be prioritized to effectively reduce the CF in China during agricultural transformation.

Internalizing externalities through net ecosystem service analysis–A case study of greenhouse vegetable farms in Beijing

One of the causes for market failure is that product externalities are not internalized into product prices. A method was put forward to internalize the externalities into the prices of agro-products, both positive (ecosystem services (ESs)) and negative (ecosystem disservices (EDSs)) externalities generated from agroecosystems were integrated into the calculation of net ecosystem service (NES) through monetary analysis. The case study of greenhouse vegetable production was carried out in conventional (CON), organic (ORG), and community-supported agriculture (CSA) farms in Beijing suburbs. The total ESs value (124 thousand USD ha−1 yr−1) of CSA farms was the highest. The total EDSs value (28.1 thousand USD ha−1 yr−1) of CON farms was the highest, and was 21 and 35 times of ORG and CSA farms, respectively. Pesticides contributed to 76% EDS value of CON farms. The NES values (without provisional ES) of CON, ORG and CSA farms were −25.4, 2.69, and 8.35 thousand USD ha−1 yr−1, respectively. The full prices of ORG (3.45 USD kg−1) and CSA (4.65 USD kg−1) vegetables were higher than those of CON (1.50 USD kg−1) vegetables. The market price of CON vegetables did not cover their value of net-negative externalities. The methodology of NES can be applied to comprehensively evaluate environmental sustainability, set fair prices for eco-friendly products, and provide a reference for eco-compensation. Further studies should be conducted, sampling more farms of different agroecosystems in different regions to test its applicability and practicality to provide substantial data for its broader application.

Comparison of agrochemicals allocation efficiency between greenhouse and open-field vegetables in China

The overuse of agrochemicals in greenhouse production system has aroused high concerns in China. Existing studies have investigated the status and determinants of agrochemicals overuse for greenhouse vegetables whereas little is known about whether the agrochemicals are allocated efficiently from economic perspective. We use a translog production function and the inputs and outputs data of vegetable production in 34 Chinese cities during 2004–2017 to calculate agrochemicals allocation efficiency for both open-field and greenhouse vegetables. We find that the agrochemicals are allocated inefficiently due to overuse for both open-field and greenhouse vegetables, whereas the overuse degree of chemical fertilizer used in greenhouse vegetables is lower than that of open-field vegetables during a growing duration. In addition, we also find that the application levels of agrochemicals for greenhouse vegetables per mu (15 mu = 1 hectare) are higher than those of open-field vegetables, but the application levels of agrochemicals for per kilogram greenhouse vegetables are significantly lower. We conclude that the overuse of agrochemicals in greenhouse production system may attribute to the year-round production of greenhouse vegetables induced by economic incentives. Therefore, reducing the number of production rotations may be an effective method to alleviate the overuse of agrochemicals in greenhouse vegetables.

Improving soil respiration while maintaining soil C stocks in sunken plastic greenhouse vegetable production systems – Advantages of straw application and drip fertigation

The absence of fertile surface soil combined with high temperature and moisture in sunken plastic greenhouse vegetable production (SGVP) leads to low soil organic carbon (SOC) storage. This limits the rapid growth of vegetable crops in SGVP as low SOC goes along with a low capacity of soils for water and nutrient retention. It also results in low soil respiration, which leads to indoor CO2 limitations during the winter crop growing season. In our experiments we explored if drip fertigation might lead to an improvement of soil respiratory activity, specifically when maize straw is incorporated additionally into the soil. To address these questions, a two-factor field experiment with four treatments was conducted across four growing seasons. The treatments are (1) Conventional flood irrigation with over fertilization (CIF), (2) CIF + maize straw (CIF + S), (3) Drip irrigation with reduced fertilization (DIF), (4) DIF + maize straw (DIF + S). Compared to CIF, DIF significantly increased water and nitrogen use efficiency by 93% and 296%, respectively. Moreover, cumulated CO2 emission was significantly lower than assimilated carbon in plant for both CIF and DIF without straw incorporation, but the opposite result was obtained when straw was added (CIF + S and DIF + S). DIF results in reduced rates of soil respiration, mainly due to significantly reduced mineralization of autochthonous SOC stocks as compared CIF. Tracing the δ13C signature of added straw into the SOC indicated that DIF leads to a larger incorporation of straw-derived C into soil than CIF. Our results show that adding straw is a suitable measure for both to meet the CO2 demand of vegetable photosynthesis and to maintain SOC stocks associated soil functions. However, the tested and widely recommended straw application rate of 3.5 t C ha−1 appears to be still too low to reverse the trend of a net mineralization of SOC stocks. Thus, our results call for targeted experiments to optimize the amount of straw addition and to explore in field experiments if the application of mixed straw and biochar produced from vegetable residues, are a suitable way forward to increase soil health of SGVP systems.

Beauveria bassiana PSUB01 simultaneously displays biocontrol activity against Lipaphis erysimi (Kalt.) (Hemiptera: Aphididae) and promotes plant growth in Chinese kale under hydroponic growing conditions

ABSTRACT The mustard aphid, Lipaphis erysimi, is a significant agricultural pest, responsible for yield losses in several vegetable crops. A desire to reduce insecticide applications in green house vegetable production systems has led to increasing use of entomopathogenic fungi to manage pests, including aphids. In this study, we evaluated the efficacy of the entomopathogenic fungus, Beauveria bassiana PSUB01, for the management of L. erysimi in Chinese kale grown hydroponically. Drenching roots and spraying foliage with B. bassiana PSUB01 conidial suspension were used as inoculation methods. Tested conidia concentrations of B. bassiana PSUB01 (108 and 109 conidia/ml) caused 87–89% mortality in L. erysimi after five days of application. The application of B. bassiana PSUB01 by root drenching colonised all treated parts (root, stem and leaf) with 64.0–96.0% colonisation (based on number of samples tested) in different part of tested plants during 7–21 days after inoculation. The application of B. bassiana PSUB01 on Chinese kale by either foliar spray or foliar spray + drenching of roots had reduced the fecundity of L. erysimi with very few progeny during 6–14 days of treatment. Also, application of B. bassiana PSUB01 by drenching of roots or by combination of foliar spray + drenching of roots enhanced plant growth parameters significantly except root length. These results suggest that B. bassiana PSUB01 could be included as part of an integrated pest management (IPM) plan for the management of L. erysimi under hydroponic production of Chinese kale and other vegetable crops.