Komatsuna Research Articles

Effects of Sugarcane Bagasse Biochar on Ammonium and Nitrate Adsorption and Leaching in a Japanese Tropical Soil Cropped with Japanese Mustard Spinach (Brassica rapa)

This study investigated the dynamics of ammonium-nitrogen (NH4+-N) and nitrate-nitrogen (NO3–-N) adsorption and leaching in a Japanese tropical soil amended with sugarcane bagasse biochars (SBBs) in the presence of plant. Adsorption and column leaching studies were conducted in a laboratory in Japan, and the column study was performed for 21 days. Biochar was produced from sugarcane bagasse at the maximum pyrolysis temperatures of 400°C (SBB400) and 800°C (SBB800) for use in the experiments. Adsorption isotherms for NH4+-N and NO3–-N were developed for soil only, SBB400-amended soil, and SBB800-amended soil. Column leaching study included 6 treatments: fertilizer only, fertilizer and plant, fertilizer and SBB400, fertilizer and SBB400 and plant, fertilizer and SBB800, fertilizer and SBB800 and plant. This study showed that soil and SBBs-amended soils fitted well into the Langmuir adsorption model for NH4+-N and NO3–-N (r2= 0.983–0.994 and 0.956–0.970, respectively). Application of SBBs to soil significantly decreased cumulative NH4+-N leached from the soil (P < 0.05) because of increased adsorption capacity due to high acid functional groups and increased soil water holding capacity (WHC) due to high specific surface areas and pore volumes, regardless of the presence of plant. However, the SBBs application did not affect the adsorption capacity for NO3–-N because of negatively charged surfaces. However, cumulative NO3–-N leached was significantly reduced (P< 0.05) due to increased soil WHC, regardless of the presence of plant. Therefore, more soil water contents retained and less NO3–-N leached from the soil may have contributed to greater plant growth with the SBBs application. This study showed that the SBBs application to soil could enhance adsorption capacity for NH4+-N but not for NO3–-N, nevertheless increase soil WHC and reduce leaching of both NH4+-N and NO3–-N, thus contributed to increased plant growth.

Temperature dependence of feeding activity in the invasive freshwater snail Pomacea canaliculata: implications for its response to climate warming

AbstractPomacea canaliculata, a freshwater snail native to South America, has become widely naturalised in many countries, causing serious damage to agricultural and native ecosystems. Although climate warming is likely to expand the distribution of this species, limited information exists regarding its impact on feeding activities. In this study, we examined the effects of temperature on the feeding activity of this species and estimated the impact of climate warming on its feeding potential. The feeding activity was determined by measuring the amount of standard food (Japanese mustard spinach, komatsuna) ingested at different temperatures. It tended to increase from 15 to 25 °C but became almost stable from 25 to 35 °C. The respiration rate determined by the O2 consumption rate, showed a similar response to temperature. Based on these findings, we constructed a simple model to estimate the relative feeding activity using climatic data recorded at meteorological stations throughout the Japanese Archipelago. The model estimated that, with warming of + 2 °C, annual feeding potential (relative value) increased by 21.1% at the present northern distribution limit of this species. The effect of warming on percentage increase in feeding potential was estimated to be smaller at the southern distribution limit (9.9%), although the absolute feeding potential was larger than that at the northern sites. The model also suggested that if this species expanded its northern distribution range as a result of climate warming, it would have a high feeding potential comparable to that of the southern regions.

Utilization of lysed and dried bacterial biomass from the marine purple photosynthetic bacterium Rhodovulum sulfidophilum as a sustainable nitrogen fertilizer for plant production

Plant-based agricultural systems rely heavily on inorganic nitrogen (N) fertilizers to increase yields and ensure food security for the rapidly growing global population. However, the production and overuse of synthetic fertilizers lead to significant amounts of greenhouse gas emissions, causing a critical need for the development of alternative and sustainable organic N fertilizers. Here, we demonstrate the effective use of lysed and dried bacterial biomass from the marine purple photosynthetic bacterium Rhodovulum sulfidophilum as an alternative source of N fertilizer for the cultivation of Japanese mustard spinach (komatsuna, Brassica rapa var. perviridis). To assess the suitability of this processed bacterial biomass, containing approximately 11% N, as a N fertilizer, we examined the effects of its application on plant germination and growth (measured by leaf chlorophyll, maximum leaf length, and dry weight) under two different temperature regimes, comparing it to that of a conventional N-containing mineral fertilizer. Application at rates up to four times that of the mineral fertilizer had no negative effects on seed germination and plant growth. The bacterial biomass had to be applied at approximately twice the rate of mineral fertilizer to obtain similar plant growth parameters, roughly corresponding to the predicted 62% rate of mineralization of the bacterial N. Our findings confirm the ability of plants to take up N from the lysed and dried biomass of marine purple photosynthetic bacteria, demonstrating the potential for using R. sulfidophilum as a source of N fertilizer.

137Cs contamination of Japanese mustard spinach by resuspended particles in areas with different contamination conditions

137Cs contamination of Japanese mustard spinach by resuspended particles in areas with different contamination conditions

Effect of plastic mulch residue on plant growth performance and soil properties

Plastic mulch is widely utilized for weed control, temperature regulation, soil erosion prevention, disease management, and soil structure improvement, ultimately enhancing crop quality and yield. However, a significant issue with conventional plastic mulches is their low recycling rates, which can cause plastic residue to build up, thereby damaging soil quality and reducing crop yield. The emergence of biodegradable films offers a promising solution to mitigate this issue and reduce soil pollution. However, its potential effects on soil properties and plant performance remain unclear. In this study, low-density polyethylene (LDPE) and poly (butylene succinate-co-butylene adipate) (PBSA) were used to observe the effect of plastic mulch residues on soil properties and plant growth performance via potting experiment. Additionally, the interaction effects of compost and biochar as soil amendments with plastic mulch residues were also evaluated. The result of this study revealed that the type of plastic significantly affected the total nitrogen and magnesium uptake; however, the morphological traits of the tested plant (Japanese mustard spinach) were not significantly affected. The addition of compost and biochar led to a significant increase in both shoot and total dry weight of the plant, indicating a positive effect on its growth. The results of the two-way ANOVA indicated a significant influence of plastic type on dissolved phosphate (PO43−) levels and soil dehydrogenase activity (DHA). The interaction effect (plastic type with soil amendment) was statistically significant only for soil DHA. Neither plastic mulch residues nor soil amendments significantly affected other soil chemical properties. However, long-term experiments to systematically investigate the long-term effects of plastic residues are necessary.

Fecundity of diamondback moth females when offered honey with pyridalyl, a selective insecticide

AbstractWe previously reported that the presence of pyridalyl, a selective insecticide, in aqueous honey (50% v/v) negatively affects the survival of diamondback moth (Plutella xylostella: DBM) adults. However, it remains unclear whether toxicity of pyridalyl in aqueous honey affects the fecundity of adult female DBMs. We analysed the survival and fecundity of adult DBM under the water, honey or honey + pyridalyl conditions in glass tubes containing Japanese mustard spinach (Brassica rapa: Komatsuna) leaves for 10 days. The survival of adults under the honey (50% v/v) and honey + pyridalyl (100‐fold dilution) conditions was significantly higher and lower, respectively, than under the water condition during the experimental period. The number of eggs laid by DBM females each day (fecundity) under the water condition was significantly lower than that under the honey condition throughout the experimental period, except on day 1. In contrast, the numbers under the water and honey + pyridalyl conditions were not significantly different, except on day 2 (the honey + pyridalyl condition was significantly lower). To study the effects of plants grown in pots on the survival and fecundity of DBM females, we conducted experiments using acrylic cages containing potted komatsuna plants. The survival trends under the honey, and honey + pyridalyl conditions in the cages were similar to those in the glass tubes. Fecundity was evaluated based on the total number of subsequent generations (DBM larvae and pupae) on day 10. The numbers were significantly higher in the honey condition than in the water condition. In contrast, the number in the honey + pyridalyl condition was not significantly different from that in the water condition. Given our previous findings that the longevity and fecundity of Cotesia vestalis, an effective natural enemy of DBM larvae, remained unaffected by the presence of pyridalyl in honey as a food supply, our research suggests that introducing devices providing honey infused with pyridalyl in greenhouses as a nutritional source for C. vestalis could be an effective biological control strategy for managing DBM populations within greenhouse environments.

Elemental concentrations in green vegetables from the perspective of urolithiasis risk

Although green vegetables are valuable sources of essential elements, and are safe in that they lack harmful elements, they are high in oxalic acid, increasing the risk of urolithiasis. We performed elemental analyses on spinach (Spinacia oleracea L), Malabar nightshade (Basella alba), and water Morning Glory (Ipomoea aquatica), which contain large amounts of oxalic acid, and compared the data to those of Japanese mustard spinach (Brassica rapa var. perviridis), which is the second most commonly consumed green vegetable (after spinach) in Japan. We focused on concentrations of Ca, Mg, and Sr that suppress the formation of ureteral stones (calculi). The calcium concentration in spinach was [Formula: see text]g/g in leaves and [Formula: see text]g/g in stalks, and the level in Japanese mustard spinach were [Formula: see text]g/g in leaves and [Formula: see text]g/g in stalks. The overall Sr concentration in Japanese mustard spinach was thus 10-fold higher than in spinach, but the Mg concentration was lower than that in spinach. The concentrations of Ca and Sr in Malabar nightshade and water Morning Glory were 3- to 5-fold higher than in spinach. As the former vegetables are consumed much less often than spinach, the risk of urolithiasis is low. We explored how the concentrations of these elements changed after boiling.

Elemental concentrations of seven types of green vegetables grown on small-scale farmlands in rural areas of Japan: Differences according to the type and place of production

We collected seven types of green vegetables produced in 11 areas of Japan and analyzed their elemental concentrations. Halogen analyses were performed with and without prior chemical treatment. The most popular type of spinach exhibited the highest concentrations of Mg, K, and Zn, and the lowest concentrations of alkaline earths (Ca and Sr) and halogens (Cl and Br). Japanese mustard spinach, the second most consumed type of spinach in Japan, exhibited the highest concentrations of P, S, Ca, Fe, and Br and adequate amounts of other essential elements. The other five green vegetables had unique elemental concentrations. In particular, radish had the highest concentrations of Ca, Na, and Cl and the lowest concentrations of Mg, P, Cu, and Zn. Leaves and stalks were separately analyzed. Fe, Cu, Zn, and Mn concentrations tended to be higher in leaves, and K, Na, and Rb concentrations were higher in stalks. Halogen (Cl and Br) concentrations in Japanese mustard spinach produced on farmland near the coast were remarkably high, suggesting an effect of sea salt. However, even in green vegetables produced near the coast, halogen uptake clearly differed by production area. The concentrations of Cl and Br in Japanese mustard spinach produced in two coastal areas were very high and were not removed by washing, but were mostly lost after boiling samples from Taneichi for 3[Formula: see text]min. In contrast, there was no difference in Na concentrations among vegetables produced in coastal and inland areas. The concentrations of essential elements such as Mg, Ca, and Fe were clearly higher in green vegetables from small- versus large-scale production areas, perhaps attributable to differences in the farming methods employed.

Thermally modified bamboo-eggshell adsorbent for phosphate recovery and its sustainable application as fertilizer

Phosphate recovery from wastewater using readily available biowaste-based adsorbents is beneficial for both eutrophication control and waste management. Bamboo char has a high-density porous structure and eggshell contains CaCO3 with high affinity for phosphate. The combination of calcined bamboo and eggshell is a potential adsorbent for P recovery that has not been tested previously. Because bamboo char and eggshell both are popular for soil amendment, a P-loaded bamboo and eggshell composite is a promising fertilizer for long-term soil improvement. In this work, the feasibility of calcined bamboo and eggshell (BE) for P recovery and its use as fertilizer were investigated. The adsorption capacity and mechanism were examined using adsorption kinetic, isotherm, and thermodynamic analysis. The kinetic study showed that the experimental data sets were fitted best by a pseudo second-order model, indicating chemisorption. The Langmuir isotherm model estimated maximum adsorption capacities of 95.14 and 98.40 mg/g for BE 1:1 and 2:1 adsorbent. Monolayer adsorption occurred on a homogenous surface. The adsorption reaction was non-spontaneous at 298 K and exothermic for the BE 1:1 and 2:1 adsorbent, and the calculated Langmuir separation factor indicated favorable conditions for P adsorption. The desorption study showed lower P desorption capacity in water than in neutral ammonium citrate. P-loaded eggshell-modified bamboo char was an effective slow-release fertilizer for Japanese mustard spinach cultivation, which is a sustainable and environment friendly use of P-loaded materials.

137Cs transfer from soils contaminated by resuspended particles to Japanese mustard spinach in difficult-to-return zone of Fukushima

137Cs transfer from soils contaminated by resuspended particles to Japanese mustard spinach in difficult-to-return zone of Fukushima

Valorization of Solid Food Waste as a Source of Polyunsaturated Fatty Acids Using Aurantiochytrium sp. L3W

PurposeThis study aimed at valorizing solid food waste containing docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).Methods Aurantiochytrium sp. L3W that produces DHA and EPA was cultivated on eight types of solid food waste: sake lees (SL), crown daisy, Japanese mustard spinach (JMS), soy sauce residue, lemon peel (LP), orange peel, grape skin, and Hiroshimana old pickle (HOP). The biomass mixture of the remaining food waste and strain L3W was analyzed for DHA and EPA. To characterize the types of food waste, the leachability of dissolved organic carbon (DOC) and dissolved nitrogen (DN) was compared.ResultsThe strain L3W grew on both pasteurized and unsterilized food waste such as SL and JMS. Elution of DOC and DN from the food waste might be a factor affecting the growth of strain L3W. However, the strain L3W might utilize solid-state organic compounds in JMS. Despite the unsterile conditions, the biomass mixture of SL contained both DHA and EPA, whereas DHA was found in the biomass mixtures of JMS, LP and HOP, thereby confirming the valorization of these types of solid food waste. Unsterile mass cultivation of the strain L3W using SL and HOP in a 200 L tank also produced a biomass mixture containing 12.6 mg-DHA/g and 0.217 mg-EPA/g. These DHA and EPA contents were 1500-times and 37-times higher, respectively, than that in commercial poultry feed, indicating that the biomass mixtures could be used as an additive in poultry feed.Graphical Abstract

Sustainable Plant Growth Promotion and Chemical Composition of Pyroligneous Acid When Applied with Biochar as a Soil Amendment.

The pyrolysis of biomass material results in pyroligneous acid (PA) and biochar, among other by-products. In agriculture, PA is recognized as an antimicrobial agent, bio-insecticide, and bio-herbicide due to antioxidant activity provided by a variety of constituent materials. Application of PA to crop plants and soil can result in growth promotion, improved soil health, and reduced reliance on polluting chemical crop inputs. More detailed information regarding chemical compound content within PA and identification of optimal chemical profiles for growth promotion in different crop species is essential for application to yield effective results. Additionally, biochar and PA are often applied in tandem for increased agricultural benefits, but little is known regarding the optimal proportion of each crop input. This work reports on the effect of combined applications of different proportions of PA (200- and 800-fold dilutions) and chemical fertilizer rates (100%, 75%, 50%, and 0%) in the presence or absence of biochar on Komatsuna (Brassica rapa var. perviridis, Japanese mustard spinach) plant growth. To elucidate the chemical composition of the applied PA, four different spectroscopic measurements of fluorescence excitation were utilized for analysis—excitation-emission matrix, ion chromatography, high-performance liquid chromatography, and gas chromatography-mass spectrometry. It was determined that PA originating from pyrolysis of Japanese pine wood contained different classes of biostimulants (e.g., tryptophan, humic acid, and fulvic acid), and application to Komatsuna plants resulted in increased growth when applied alone, and in different combinations with the other two inputs. Additionally, application of biochar and PA at the higher dilution rate increased leaf accumulation of nutrients, calcium, and phosphorus. These effects reveal that PA and biochar are promising materials for sustainable crop production.

Behaviour of nutrients released from crystalline minerals of artificial potassium silicate fertilizer and their supply to the Japanese mustard spinach (Brassica rapavar.perviridis)

AbstractArtificial potassium silicate fertilizer (PSF) is a typical slow‐release potassium fertilizer. However, the exact minerals that are released by PSF and the nutrients that are made available to plants remain unclear. This study quantitatively investigated the behaviour of nutrients released from PSF by the batch‐release test and their supply to plants by the plant growth tests, respectively, to determine the quantitative relationship between nutrients released from PSF and taken up by the plant. X‐ray diffraction (XRD) analysis showed that kalsilite, åkermanite, and potassium–magnesium silicate were the most abundant crystalline minerals in PSF. The XRD peaks of åkermanite and potassium–magnesium silicate were absent after citric acid extraction at a liquid/solid ratio of 20 to 100 (CA20 and CA100). Magnesium‐use efficiencies in PSF (11%) and residue treatments after ammonium acetate extraction (AC, 10%) were higher than those in residue treatments after CA20 (1.8%) and CA100 (6.0%). Potassium (%) released by AC in the batch‐release test (4.5%) was compatible with the difference of potassium‐use efficiencies between the treatments of PSF (21%) and the AC‐residue (16%). Likewise, potassium (%) released by CA20 (8.8%) was lower than the difference of potassium‐use efficiencies between the treatments of PSF (21%) and CA20‐residue (7.9%). This study suggests that potassium is rapidly released from potassium–magnesium silicate in PSF and is readily available to plants.

Assessment of Close-range Remote-sensing Based Methods for Field Survey of Japanese Mustard Spinach (Komatsuna) Growth

Assessment of Close-range Remote-sensing Based Methods for Field Survey of Japanese Mustard Spinach (Komatsuna) Growth

Effects of yeast fermented coffee grounds extract on the growth of Japanese mustard spinach

Effects of yeast fermented coffee grounds extract on the growth of Japanese mustard spinach

Intermittent Root Flushing with Ozonated Water Promotes Growth of Japanese Mustard Spinach (Brassica rapa var. perviridis) grown in a Nutrient Film Technique Hydroponic Culture—Preliminary Results

ABSTRACT Japanese mustard spinach with 4–5 unfolded leaves were transplanted in a nutrient film technique hydroponic system to investigate the effects of washing roots intermittently with ozonated water (OW) on plant growth. The high concentration of OW generated electrolytically was mixed in the nutrient solution tank, showed 5.8 mg.L−1, and circulated through the culture beds for 1 h every week. After washing the roots with OW or tap water (TW) as a control for 1 h, Otsuka house A solution (NO3-N: 16.8 me.L−1, NH4-N: 1.8 me.L−1, P: 5.1 me.L−1, K: 8.6 me.L−1, Ca: 8.2 me.L−1, Mg: 3.0 me.L−1) at 1.2 dS.m–1 was provided for plant cultivation in hydroponic culture systems. The OW or TW was replaced every week. The fresh and dry weights of the leaves, number of leaves, leaf length, and leaf width of plants treated with OW were significantly higher than those of the plants treated with TW at 1, 2, and 3 weeks after transplanting (WAT). The ratio of the shoot and root dry weights at 1, 2, and 3 WAT was significantly higher in plants grown in the OW flushing treatment compared with the control treatment. However, the roots dry weights were not significantly different between the OW- and TW-treated plants. Moreover, the number of coliform bacteria and aerobic plate count (APC) in the solution and plants were not significantly different between the two treatments. These results indicate that washing roots intermittently with 5.8 mg.L−1 dissolved ozone concentration of OW for 1 h per week promotes aerial plant growth without physiological disorder and is not accompanied by a decrease in the number of coliform bacteria and APC in the solution and plants.

Consumers’Preference Heterogeneity and Purchase Motivation of Organic Vegetables

Sustainability is currently one of the most important issues for agricultural activities. This study used scanner panel data to analyze consumers’ evaluation of organic agricultural products. The main aim was to describe consumers’ preference heterogeneity and purchase motivation for organic vegetables. The data set combined purchase history of Japanese mustard spinach and consumers’ demographics and attitudes for food were analyzed using a random parameter multinomial logit model. The results revealed that the distribution of marginal willingness to pay（MWTP）for organic products was wider than specially cultivated agricultural products, which are cultivated with 50% usage of chemicals. In addition, consumers concerns about food safety issues and public benefit had higher MWTP for organic products. This may indicate that consumers of organic vegetables are motivated by food safety concerns and willingness to contribute to mitigate environmental load in agricultural production.

Rapid and non-destructive seed viability prediction using near-infrared hyperspectral imaging coupled with a deep learning approach

Seeds are the basis of the agricultural food industry, greater insights into seed viability before sowing could improve storage management and field performance. In the present study, we aimed to address this issue by using highly cost-efficient near-infrared hyperspectral imaging (NIR-HSI) and a convolutional neural network (CNN) deep learning approach. An NIR-HSI camera was used because it can recognize both molecular vibration information (i.e. chemical component differences) and its spatial distribution in each seed sample; this camera is much more informative than a regular RGB digital camera. Using this technology, the emphasis of this study was firstly to provide a methodology for enhancing the interpretability of viable and non-viable seeds via principal component analysis (PCA) and support vector machine (SVM) viability classification analysis of NIR-HSI data. A CNN was then constructed to“cognize” the differences in viable and non-inviable seeds and classify them automatically. Experimental results indicate that the methodology produces a ~90% classification accuracy for both a five-fold cross-validation set and a test set of naturally aged Japanese mustard spinach seeds. Therefore, this study provides a new strategy for effective and practical seed viability prediction.

Acceleration of germination and early growth of plant seeds by high frequency and low intensity alternating electric fields

The purpose of this study was to accelerate germination of plant seeds with application of a high frequency alternating electric field. In the present study we show that low-intensity (0.05–1 Vpp/cm) and high frequency (10–100 MHz) alternating electric fields accelerate seed germination. We found that 1 Vpp/cm (peak to peak voltage/cm), 100 MHz alternating electric field application for 10 h significantly shortened germination time of arugula, Japanese mustard spinach, and pea seeds, respectively. In arugula and Japanese mustard spinach seeds at 24 h incubation and pea seeds at 32 h incubation after beginning of the application, the germination rates of the electric field applied plant seeds were enhanced 1.5–2.2 times compared to the untreated seeds, respectively. After 72 h of the incubation, the 1 Vpp/cm, 100 MHz alternating electric field for 10 h significantly increased 1.4 folds of culm lengths in the arugula, the Japanese mustard spinach, and the pea seeds compared with those of the untreated seeds.

Environmental impacts and consumer preference for sustainably cultivated Japanese mustard spinach, komatsuna

Sustainable agriculture is spreading in Japan in response to growing concerns about the environmental burden of the agriculture sector, but less than 1% of the total crop area for each vegetable in Japan is grown sustainably. Environmentally friendly agricultural products are produced by using organic and low-input farming techniques; low-input farming aims to reduce chemical inputs, such as fertilizers, pesticides, and herbicides, by half. Here, we used komatsuna (Japanese mustard spinach, Brassica rapa var. perviridis) as a model vegetable to study the environmental impact of low-input farming and ways to promote the purchase of organically and low-input farmed vegetables. We first assessed greenhouse gas emissions resulting from organic, low-input, and conventional farming of komatsuna. We also evaluated the effectiveness of providing consumers with detailed farm management and seasonality information to market organically and low-input farmed vegetables. We estimated marginal willingness-to-pay (MWTP) using choice-based conjoint analysis, based on attributes of price, fertilizer use, pesticide use, and region of origin. For seasonality, the questionnaire incorporating these attributes was conducted twice: once assuming purchasing in season, the other out of season. The greenhouse gas emissions of organic farming per area (196.7 kg CO2-eq/10 a/year) and per yield (72.3 kg CO2-eq/t/year) were less than those of low-input (322.6 kg CO2-eq/10 a/year, 120.7 kg CO2-eq/t/year) and conventional (594.0 kg CO2-eq/10 a/year, 220.7 kg CO2-eq/t/year) farming. MWTPs were highest for pesticide-free komatsuna (76.9 yen out of season, 66.2 yen in season), followed by full organic fertilizer (66.0 yen out of season, 63.4 yen in season), half organic fertilizer (35.8 yen out of season, 19.8 yen in season), and half pesticide (29.2 yen out of season, 21.0 yen in season). Consumers showed greater preference for organically and low-input farmed komatsuna out of season than in season. Consumers were more interested in pesticide information than in fertilizer and region of origin information. Our findings suggest that providing detailed cultivation and seasonality information would be a beneficial consumer communication tool to increase the market for sustainable agricultural products.