Recycling of Chicken and Duck Litter Ash as a Nutrient Source for Japanese Mustard Spinach

ABSTRACT

Recycling combusted poultry litter ash as a soil amendment would potentially ameliorate problems normally associated with poultry waste management. We evaluated the effect of chicken litter ash (CLA) and duck litter ash (DLA) as nutrient sources for Japanese mustard spinach (Brassica rapa L. var. perviridis) grown on a sand dune soil. Chicken and duck litter were ashed at five temperatures: 200, 400, 600, 800, and 900°C and the resulting ash samples were applied at the rate of 100 kg phosphorus (P) ha^?1. Laboratory analysis showed the highest P extraction with citric acid from CLA and DLA obtained at 600°C. Chicken litter ash was richer in P and potassium (K) than DLA but the later contained more calcium (Ca) and magnesium (Mg). The amount of ammonium acetate soluble calcium (Ca), magnesium (Mg), and K recovered increased with increasing temperature except for Ca and Mg at the highest temperatures, 800 and 900°C. Plants grown in pots with the CLA and DLA obtained at 400°C had the highest P concentration, yielding significantly more biomass with dense green leaf color but on average, the DLA amended soil had greater biomass. However, the P level was higher in CLA treated plants than DLA due to the higher available P level (citric acid soluble). Increases in electrical conductivity and pH of the soil were noted after harvest due to litter ash application. Our experiment demonstrated that poultry litter is potential source of P and other nutrients for horticutural crops.     

NITRATE IN LEAF PETIOLE AND BLADE OF SPINACH CULTIVARS AND ITS RELATION TO BIOMASS AND WATER IN PLANTS

A pot experiment was carried out, with 30 spinach cultivars to determine nitrate accumulation in leaf blade and petiole, and its relationship to biomass and water in plants. Results showed that the fresh weight proportion of blade to shoot was higher than that of petiole. Furthermore, a higher positive correlation was found between fresh weights of blades and shoots than that of petioles and shoots. Unlike biomass, nitrate-nitrogen (N) concentration and total amount of nitrate-N accumulated in petiole were significantly higher than those in blade, and petiole was obviously the main organ for nitrate accumulation. Differences of nitrate-N concentration in petiole and the observed positive correlation between nitrate-N concentrations in petioles and shoots were more significant than that in blades and shoots. Nitrate-N concentration in petiole was also significantly correlated with fresh and dry shoot weight and total amount of water in shoots. However, this relationship was not found for blade.     

NITRATE ACCUMULATION IN SPINACH AS INFLUENCED BY SULFUR AND PHOSPHORUS APPLICATION UNDER INCREASING NITROGEN LEVELS

Nitrate (NO₃) accumulation by spinach was studied under increasing nitrogen (N) levels (60, 120 and 240 kg N ha^?1) along with sulfur (45 kg S ha^?1) and phosphorus (P; 90 kg P₂O₅ ha^?1) application. Plants were harvested at 50 and 65 days after sowing. Plant samples were analyzed for NO₃-N and total N, P, S, potassium (K), calcium (Ca), and magnesium (Mg). Radio assay of 35S was done to estimate percent sulfur derived from fertilizer and percent fertilizer sulfur utilization. Spinach maintained a very high level of NO₃-N in its tissue throughout the growing period. NO₃-N was increased with increasing nitrogen level and was reduced with phosphorus and sulfur application and also with advancement in growth. Total N, P, S, K, Ca and Mg uptake were increased with increasing nitrogen levels as well as with application of sulfur and phosphorus. Sulfur application caused increase in percent sulfur derived from fertilizer and percent utilization of fertilizer sulfur.     

Effect of drip fertigation system on nitrate control in spinach Spinacea oleracea L.

(pp. 9–16)

Nitrate is a major form of uptake and storage of nitrogen for upland plants. However, nitrate is harmful to human health · ingestion of a large quantity can lead to cancer or methemoglobinemia. The effectiveness of drip fertigation for reducing nitrate in spinach was investigated in this study. Fertilizer application can be controlled effectively by drip fertigation. Field experiments were conducted in September 2002 and June 2003 at the National Agricultural Research Center for Hokkaido Region. Two spinach cultivars were grown in each cultivation in a plastic greenhouse, and the plants were treated with 4, 8 or 12 g N m^?2 of fertilizer applied by drip fertigation, and with 8, 12 or 16 g N m^?2 of fertilizer applied as basal application. The nitrogen was applied at the rate of 0.15 g m^?2 per day for the first 15 days, and 0.25 g m^?2 for the following 23 days in 8 g N m^?2 treatment of drip fertigation.

The rate of growth and nitrogen absorption of spinach in the early growth stages was very slow, but they increased quickly from around day 23 after sowing. The amount of nitrogen absorbed by spinach was close to the amount applied in 8 g N m^?2 treatment. This treatment resulted in spinach with a low nitrate concentration without reduction in yield. Although the same results were obtained by treatment with 8 g N m^?2 of fertilizer by basal application, there was a tendency for nitrate concentration to fall further with drip fertigation. The rate of nitrate-nitrogen to total-nitrogen rose sharply when the total-nitrogen concentration was higher than 42 g kg^?1 DW in leaf blade and 18 g kg^?1 DW in leaf petiole. The total-nitrogen concentration was lowered a little and for that reason the rate of nitrate-nitrogen to total-nitrogen was lower in spinach treated with 8 g N m^?2 of drip fertigation than in spinach treated with 8 g N m^?2 of basal application. Thus, drip fertigation was considered to reduce nitrate more stably.     

Alleviation of cadmium phytotoxicity by magnesium in Japanese mustard spinach

Abstract

To clarify the mechanism of Magnesium (Mg) in alleviating cadmium (Cd) phytotoxicity, Japanese mustard spinach (Brassica rapa L. var. pervirdis) was grown for 10 days after treatment in hydroponics in a growth chamber under natural light. The treatments were: (1) nutrient solution alone (Control), (2) 10 mmol L^?1 Mg (High-Mg), (3) 2.5 µmol L^?1 Cd (Cd-toxic), (4) 2.5 µmol L^?1 Cd plus 10 mmol L^?1 Mg (Mg-alleviated). The Cd-toxic treatment showed substantial growth retardation and chlorosis of young leaves, such symptoms were not observed in Mg-alleviated plants. Magnesium-alleviated plants showed higher shoot growth, more than twofold, and decreased shoot Cd concentration, approximately 40%, compared with Cd-toxic plants. This increase in shoot growth and simultaneous decrease in shoot Cd concentration may explain the alleviation of Cd toxicity with Mg in Japanese mustard spinach. In Cd-toxic plants, concentrations of K in shoots and Zn in both shoots and roots increased compared with the other three treatments. Concentrations and accumulations of Fe and Mn in shoots decreased significantly in the Cd-treated (Cd-toxic and Mg-alleviated) plants compared with the control and High-Mg plants. Thus, the application of high amounts of Mg in the nutrient solution can alleviate Cd toxicity in plants.     

浅水土表覆盖秸秆对缓解土壤盐渍化及水生蔬菜生长的影响

为探究浅水土表覆盖秸秆对土壤盐渍化的缓解效果和对蕹菜生长的影响,在大棚内利用硝态氮含量均在1 200 mg·kg^-1以上的重度盐渍化土壤采用塑料栽培箱浅水种植蕹菜,以不覆盖秸秆作对照,设置覆盖切段5 cm的水稻秸秆150 g（7 500 kg·hm^-2,R150₅）、切段40 cm的小麦秸秆150 g（7 500 kg·hm^-2,W150₄₀）、小麦整株秸秆150 g（7 500 kg·hm^-2,W150）和切段10 cm小麦秸秆300 g（15 000 kg·hm^-2,W300₁₀）共5种处理,测定不同处理下土壤硝态氮、有机碳、全氮、全磷、全钾含量及蕹菜的产量和品质等指标。结果表明,覆盖秸秆处理土壤的硝态氮含量较对照均显著降低,降幅均在50%以上。除W300₁₀处理土壤有机碳含量增加外,其余覆盖秸秆处理土壤的有机碳含量均降低,但降幅小于对照。除W150₄₀处理外,其余处理土壤的速效钾含量均增加。覆盖秸秆处理的蕹菜总产量均高于对照,其中,R150₅处理的增产效果最显著。综上所述,浅水土表覆盖秸秆消耗了土壤中富余的硝酸盐,缓解了土壤盐渍化,同时为土壤提供了有机碳,增加了土壤速效钾含量,使蕹菜产量显著提高。     

有机无机肥料配施对盆栽菠菜生长和土壤供氮特性的影响

通过盆栽试验研究了有机肥与无机肥配施对菠菜产量、品质及土壤供氮特性的影响。结果表明,收获时菠菜生物量由大到小依次为:处理4(5%(占施氮量百分比)尿素与95%有机肥配施)、处理5(10%尿素与90%有机肥配施)、处理3(有机肥)、处理2(无机肥)、处理1(不施肥);植株氮累积量以处理5最多,其他处理趋势与生物量相同。收获时,植株维生素C含量依次为处理4、处理3、处理5、处理2、处理1,并且所有处理菠菜可食用部分硝酸盐含量均达到直接食用标准(小于432 mg.kg-1);无机肥处理比有机肥处理矿质态氮释放速度快,有机无机肥配施处理能更好地调节土壤氮素的释放;有机无机肥配施处理与有机肥处理能增加土壤微生物量碳,且增加幅度大于单施无机肥处理。     

负压灌溉对菠菜生长及水分利用效率的影响

为筛选出南方地区菠菜生长最适宜的灌溉负压值, 采用土壤盆栽试验, 以人工浇灌为对照(CK),研究3个供水负压(-5.0,-10.0,-15.0 kPa)对菠菜生长、生理指标、品质指标、水分利用效率及养分吸收的影响.结果表明:-5.0 kPa负压供水,菠菜地上部产量178.2 g/pot, 显著高于-10.0和-15.0 kPa, 与CK差异不具有统计学意义; 地下部生物量9.99 g/pot, 显著高于CK和-15.0 kPa; 根系活力419.0 μg/(g·h), 显著高于CK,-10.0和-15.0 kPa,分别提高65.3%,51.5%和91.0%;VC和可溶性糖含量分别为50.72 mg/100 g和1.74%, 较CK,-10.0和-15.0 kPa分别提高18.3%,10.5%,44.9%和6.1%,23.4%,47.5%.-5.0 kPa负压供水,水分利用效率为3.89 g/kg,显著高于CK和-15.0 kPa, 与-10.0 kPa差异不具有统计学意义;菠菜地上部氮的累积吸收量显著高于CK,-10.0和-15.0 kPa, 磷、钾累积吸收量与CK差异不具有统计学意义, 但显著高于-15.0 kPa.综合菠菜产量和水分利用效率,-5.0 kPa负压供水较适合南方地区菠菜生长发育.     

Cs对菠菜叶片光合作用影响的研究

为了揭示Cs对植物光合作用的影响机理,本文采用不同浓度的CsCl(0、1、5、10、20 mmol·L-1)和石英砂培处理菠菜幼苗15 d,分析测定了Cs在菠菜中的积累分布以及Cs对菠菜叶片叶绿素含量、光合气体交换参数、叶绿素荧光参数、类囊体膜电子传递速率、类囊体膜吸收光谱和77k低温荧光光谱的影响.结果表明:Cs处理显著降低菠菜叶片的叶绿素含量;随着Cs处理浓度的增加,尤其在处理浓度大于10 mmol·L-1时,叶片净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)以及蒸腾速率(Tr)显著下降;叶片叶绿素荧光参数分析表明,Cs处理浓度大于10 mmol· L-1时,光系统Ⅱ(PSⅡ)反应中心遭到破坏;类囊体膜电子传递活性分析表明高浓度Cs处理抑制PSⅡ放氧侧的电子传递活性;类囊体膜室温吸收光谱和77K低温荧光光谱分析表明高浓度Cs会破坏类囊体膜的结构,导致叶绿素的结合状态受损,从而使类囊体膜光能的吸收、传递和分配受到抑制,并且会导致类囊体膜上PSⅡ和PSⅠ的色素蛋白发生不同程度的降解.本研究可为Cs污染的植物修复提供一定理论依据.     

Nitrate-nitrite levels in commercially processed and home processed beets and spinach

Nitrate and nitrite content of commercially processed and home processed beets and spinach samples were analyzed using specific ion electrode and colorimetric methods. The home processed beets were found to be significantly higher in nitrate content than the commercially processed beets. This difference was attributed to differences in processing methods. Pickled and Harvard beets contained significantly lower amounts of nitrate/nitrite on a dry weight basis than the other types of processed beets, evidently due to the diluting effect of added sucrose. Home frozen spinach showed a trend toward lower nitrate content than commercially frozen spinach, although the difference was not significant. Length of storage of home processed beets and spinach did not appear to affect nitrate or nitrite content.Published as Nebraska Agricultural Research Division Journal Series 7495. Supported by funds from teh Nebraska Agricultural Research Division Project No. 91-031 and U.S.D.A. C.S.R.S. Project No. W-143.