Co-composting of sugarbeet vinasse: influence of the organic matter nature of the bulking agents used

Two composts were obtained by co-composting of a concentrated depotassified beet vinasse and two agricultural solid residues with different organic matter nature: grape marc (GM; lignin waste) and cotton gin trash (C; cellulosic waste). Composting was carried out in aerated piles with mechanical turning, in controlled conditions during 4 months. After 71 days of composting, a new addition of vinasse similar to the initial addition was made. Changes in temperature, pH and inorganic nitrogen followed a similar path for both mixtures. However, organic matter fractions showed different behaviour depending on the material co-composted with vinasse. Lower organic matter degradation was observed when GM was used as bulking agent due to its high lignin content. No phytotoxicity was detected in the end products. The chemical and physical properties of both vinasse composts suggest their possible use as fertiliser.     

Effects of nitrogen fertiliser on tree/ pasture competition during the establishment phase of a silvopastoral system

The establishment phase of an upland silvopastoral system was studied to examine the growth and nutrition of wild cherry (Prunus avium L.) trees under different nitrogen fertiliser treatments. High rates of nitrogen fertiliser exacerbated competition between trees and pasture in a dry year when low fertiliser treatments produced faster tree height growth. When herbicides were not used to control grass growth after the third growing season, tree growth was significantly reduced showing that below-ground competition may be a significant factor on stony upland soils. Tree growth was correlated with foliar nitrogen concentrations and not soil water, suggesting competition for soil nitrogen reduced tree growth. The importance of the interaction of fertiliser use with competition is considered in relation to successful establishment.     

Stem-boring Diptera in perennial ryegrass in relation to fertiliser.

Two levels of fertiliser were applied to perennial ryegrass in four equal doses according to two different time schedules. Stem-borer larvae were more frequent in plots treated with the higher rate and the relative incidence of the species varied according to fertiliser level. At the high fertiliser level the later applications resulted in an earlier increase in larval numbers and a higher larval population in the winter. At the low fertiliser level the total number of larvae was greater in the plots receiving earlier fertiliser applications due to an increase in the number of Oscinella vastator larvae. Populations of larvae were related to the tillering of the grass but not to the nitrogen content of the host plants.     

Production of 15N-Labelled Liquid Organic Fertilisers Based on Manure and Crop Residue for Use in Fertigation Studies

Large quantities of crop residue and animal manure from agricultural and livestock activities are annually produced worldwide. With proper management, these residues are potentially valuable sources of plant nutrients, mainly N. Recycling such subproducts in sustainably-based agricultural systems can minimise the use of mineral fertilisers, and hence reduce the potential risk of surface and groundwater pollution. Therefore, the purpose of this study was to obtain (small scale) two liquid labelled-organic fertilisers, an animal- and a vegetal-based organic (AO and VO, respectively) fertiliser, to be used as organic N sources in subsequent fertigation studies. Forage maize (Zea mays L.) grown under ¹⁵N-labelled fertiliser supply was used as raw material for VO fertiliser production, and also as ¹⁵N-labelled sheep feed to obtain ¹⁵N-labelled manure. The labelled faeces fraction was used as raw material for the AO fertiliser. The VO fertiliser was obtained after an acidic and an enzyme-driven hydrolysis. The AO fertiliser was obtained after acidic hydrolysis. The VO liquid fertiliser presented an N concentration of 330 mg·L^-1, 85% of total N was organic, while ammonium and nitrate N accounted for 55% and 45% of the mineral nitrogen fraction, respectively. This fertiliser also exhibited high K, Ca and S concentrations and notable values for the remaining macro- and micronutrients. The AO liquid fertiliser had a similar total N concentration (496 mg·L^-1, 82% of total N in an organic form) to that of VO, but its mineral N fraction significantly differed, which came in a predominantly (95%) ammonia form. It also had a high content of N, P, K and other macronutrients, and sufficient Fe, Zn, Mn, Cu and B levels, which suggests its suitability as a potential fertiliser. The percentage of ¹⁵N enrichment in both VO and AO liquid fertilisers exceeded 2% ¹⁵N atom excess, which enabled their use in subsequent assays run to assess nitrogen uptake efficiency.     

Use of white clover as an alternative to nitrogen fertiliser for dairy pastures in nitrate vulnerable zones in the UK: productivity, environmental impact and economic considerations

Perennial ryegrass and perennial ryegrass/white clover permanent dairy pastures are compared with respect to productivity, environmental impact and financial costs in nitrate vulnerable zones (NVZ) in the UK. With appropriate management, and utilisation of recommended perennial ryegrass and white clover cultivars, white clover is likely to stabilise at around 20% of total dry matter production in a mixed pasture. Plant dry matter production and milk production from a perennial ryegrass/white clover pasture are likely to be similar to that from a perennial ryegrass pasture receiving 200 kg N ha⁻¹ annum⁻¹ and around 70% of that obtained with perennial ryegrass supplied with 350–400 kg N ha⁻¹ annum⁻¹. Nitrate, phosphorus and methane losses from the system and decreases in biodiversity relative to a grazed indigenous sward are likely to be similar for a perennial ryegrass/white clover pasture and a perennial ryegrass pasture receiving 200 kg N ha⁻¹ annum⁻¹: nitrate leachate from both systems is likely to comply with European legislation. Greenhouse gas emissions resulting from nitrogen (N) fertiliser production would be avoided with the perennial ryegrass/white clover pasture. Within NVZ stocking rate restrictions, white clover can provide the N required by a pasture at a lower financial cost than that incurred by the application of N fertiliser.     

The effects of mixing Italian ryegrass (Lolium multiflorum) with perennial ryegrass (L. perenne) or red clover (Trifolium pratense) on the incidence of viruses

Mixing the ryegrass mosaic virus (RMV) resistant perennial ryegrass (Lolium perenne) cv. Endura with the susceptible Italian ryegrass (L. multiflorum) cv. RvP decreased infection of RvP wth RMV from 37% when grown alone to 22% when mixed. However, Endura yielded less than RvP and there was no yield benefit from mixing the two cultivars. Mixing red clover (Trifolium pratense) cv. Hungaropoly with RvP had no detectable effect on RMV incidence in RvP but did decrease the incidence of red clover necrotic mosaic virus in Hungaropoly from 9% to 1% and of white clover mosaic virus from 53-5% to 41%. The yield of the mixture was equal to that of RvP grown alone but given nitrogen fertiliser. The numbers of eriophyid mites, including Abacarus hystrix the vector of RMV, on ryegrass leaves were similar in pure and mixed swards. It is concluded that with herbage crops, the common practice of sowing mixtures of species may help control virus diseases.     

The development and endophytic nature of the fungus Heteroconium chaetospira

The root endophytic fungus Heteroconium chaetospira was isolated from roots of Chinese cabbage grown in field soil in Japan. This fungus penetrates through the outer epidermal cells of its host, passes into the inner cortex, and grows throughout the cortical cells, including those of the root tip region, without causing apparent pathogenic symptoms. There are no ultrastructural signs of host resistance responses. H. chaetospira has been recovered from 19 plant species in which there was no disruption of host growth. H. chaetospira has a symbiotic association with Chinese cabbage. The fungus provides nitrogen in exchange for carbon. These associations are beneficial for the inoculated plants, as demonstrated by increased growth rate. When used as a preinoculum, H. chaetospira suppresses the incidence of clubroot and Verticillium yellows when the test plant is post-inoculated with the causal agents of these diseases. H. chaetospira is an effective biocontrol agent against clubroot in Chinese cabbage at a low to moderate soil moisture range and a pathogen resting spore density of 10(5) resting spores per gram of soil in situ. Disease caused by Pseudomonas syringae pv. macricola and Alternaria brassicae on leaves can be suppressed by treatment with H. chaetospira. The fungus persists in the roots and induces systemic resistance to the foliar disease.     

Effects of a compost made from the solid by-product ("alperujo") of the two-phase centrifugation system for olive oil extraction and cotton gin waste on growth and nutrient content of ryegrass (Lolium perenne L.)

A pot experiment was conducted on a low-fertility calcareous soil in order to evaluate the effect on ryegrass growth and nutrient uptake of an organic fertiliser obtained by composting "alperujo" and cotton gin waste. Compost, alone and combined with nitrogen fertilisation, was added to the soil at three rates and three harvests were obtained. The compost application enhanced plant growth in the first and third harvest. However, the additional nitrogen fertilisation clearly improved soil productivity due to the scarce availability of this nutrient in the compost. Also, a general increase in the plant contents of phosphorus and potassium in the first two harvests was recorded, whereas treatments with the maximum compost rate showed the highest plant content of copper in the last two harvests. Decreases in calcium in the last two harvests, in magnesium in all of them and in iron and manganese in the last harvest were also observed.     

Enhancing Soil Organic Matter as a Route to the Ecological Intensification of European Arable Systems

Soil organic matter (SOM) is declining in most agricultural ecosystems, impacting multiple ecosystem services including erosion and flood prevention, climate and greenhouse gas regulation as well as other services that underpin crop production, such as nutrient cycling and pest control. Ecological intensification aims to enhance crop productivity by including regulating and supporting ecosystem service management into agricultural practices. We investigate the potential for increased SOM to support the ecological intensification of arable systems by reducing the need for nitrogen fertiliser application and pest control. Using a large-scale European field trial implemented across 84 fields in 5 countries, we tested whether increased SOM (using soil organic carbon as a proxy) helps recover yield in the absence of conventional nitrogen fertiliser and whether this also supports crops less favourable to key aphid pests. Greater SOM increased yield by 10%, but did not offset nitrogen fertiliser application entirely, which improved yield by 30%. Crop pest responses depended on species: Metopolophium dirhodum were more abundant in fertilised plots with high crop biomass, and although population growth rates of Sitobion avenae were enhanced by nitrogen fertiliser application in a cage trial, field populations were not affected. We conclude that under increased SOM and reduced fertiliser application, pest pressure can be reduced, while partially compensating for yield deficits linked to fertiliser reduction. If the benefits of reduced fertiliser application and increased SOM are considered in a wider environmental context, then a yield cost may become acceptable. Maintaining or increasing SOM is critical for achieving ecological intensification of European cereal production.     

Growth and uptake of nitrogen by wheat and ryegrass in fumigated and irradiated soil

Summary Wheat and ryegrass were grown in pots containing soil that had either been irradiated, fumigated with methyl bromide, fumigated with formaldehyde, or left untreated. All pots received a basal dressing of potassium, phosphorus and magnesium; response to nitrogen was tested by applying either 0, 0.177 or 0.354 g nitrogen per pot. Irradiation increased the growth of wheat and ryegrass; uptake of nitrogen was also increased in both crops. The amount of fertilizer nitrogen equivalent to the nitrogen supplied by seeds and soil (the “N value”) can be calculated from the efficiency of uptake of fertilizer nitrogen and used to allow for the effect on crop growth of the nitrogen released by irradiated soil. With wheat the increase in growth can be attributed solely to the extra mineral nitrogen released by irradiated soil. However, ryegrass grew a little better than would have been expected if the only effect of irradiation was to increase the release of soil nitrogen. Fumigation with methyl bromide or formaldehyde increased the growth of wheat and ryegrass not given fertilizer nitrogen. However, fumigation with methyl bromide left ionic bromide in the soil, and this depressed the growth of wheat receiving fertilizer nitrogen. Formaldehyde also left residues; these influenced soil metabolism and sometimes depressed the growth of plants given fertilizer nitrogen.     

Performance of Spodoptera litura Fabricius on different host plants: influence of nitrogen and total phenolics of plants and mid-gut esterase activity of the insect

Five host plants [castor, Ricinus communis (Carolus Linnaeus); cotton, Gossypium hirsutm (Carolus Linnaeus); tomato, Lycopersicum esculentum (Philip Miller); mint, Mentha arvensis (Carolus Linnaeus) and cabbage, Brassica oleracea (Carolus Linnaeus)] belonging to different families were used to study the performance of the Asian armyworm, Spodoptera litura larvae. Highest consumption of food and dry weight gain was observed in larvae fed on castor. Mint did not support optimum larval growth because of low digestibility and low efficiency of conversion of digested food to body matter. Dry weight gain ranged from 26.64 mg on mint to 86.80 mg in castor. These differences tend to be related to nitrogen and total phenolics content of the leaf tissues; however, the most clear-cut correlation is an inverse one between the host plant preference and the ratio of total phenolics to nitrogen in the leaf tissues. Mid-gut esterase activity in larvae showed an increasing trend with the increase in total phenolics: nitrogen ratio in the test plants and the order of mid-gut esterase activity in larvae was mint > cabbage > cotton > tomato > castor.     

Phytotoxicity of the tetramic acid metabolite trichosetin

Trichosetin, a tetramic acid-containing metabolite produced in the dual culture of Trichoderma harzianum and Catharanthus roseus (L.) G. Don callus, was subjected to phytotoxicity assays. In seedling growth assays, trichosetin inhibited root and shoot growth of all five plant species tested by damaging the cell membrane, as evidenced by the dose-dependent increase in electrolyte leakage and lipid peroxidation. Vital staining of trichosetin-treated Nicotiana tabacum BY-2 cells, with rhodamine 123, showed a weaker green fluorescence compared to controls indicating damaging effects on mitochondria. FDA-PI staining, to determine cell viability, indicated that cells of the trichosetin-treated roots were mostly dead.     

施用泥炭对风沙土改良及蔬菜生长的影响

通过盆栽试验比较了施用不同剂量的泥炭(0％、2％、5％、8％及10％)对风沙土改良的效果和对白菜生长及产量的影响。结果表明,泥炭能增强风沙土的持水能力,降低土壤的pH值,增加土壤中有机质、全氮、速效氮和速效磷等的含量;白菜根系长度、生物量、高生长和地上部分的生物量均有增加,其中8％泥炭处理为最佳,其根系长度、根鲜重、干重、高生长、地上部分鲜重、干重依次比对照增加71％、402％、464％、107％、847％和1001％;同时施用泥炭还有利于提高白菜干物质的积累及其品质。     

The range of mobility of the non‐cellulosic polysaccharides is similar in primary cell walls with different polysaccharide compositions

The molecular mobility of the non‐cellulosic polysaccharides in hydrated primary cell walls of three monocotyledons (Italian ryegrass, pineapple and onion) and one dicotyledon (cabbage) was studied using solid‐state ¹³C NMR spectroscopy. These cell walls were chosen as they have different non‐cellulosic polysaccharide compositions. By exploiting proton rotating‐frame and spin‐spin relaxation time constants three different cell wall domains which responded to cross‐polarization experiments were identified. Most of the non‐cellulosic polysaccharides occupied a mobile domain (C), but some occupied a partly rigid domain (B). Crystalline cellulose occupied a highly rigid domain (A). In the cell walls of Italian ryegrass and pineapple, domain C contained mainly glucuronoarabinoxylans and small amounts of rhamnogalacturonans; domain B contained small amounts of xyloglucans and galacturonans. However, in the cell walls of onion and cabbage, domain C contained mainly rhamnogalacturonans with galactans (in onion) or arabinans (in cabbage) as side chains; domain B contained galacturonans and xyloglucans. Single‐pulse excitation was used on Italian ryegrass and cabbage cell walls to reveal signals from a highly mobile fourth domain (D). In Italian ryegrass cell walls domain D contained glucuronoarabinoxylans and small amounts of rhamnogalacturonan, whereas in cabbage cell walls it contained arabinan side chains of rhamnogalacturonans. A novel feature of the research was the use of solid‐state ¹³C NMR spectroscopy to examine the molecular mobilities of the polysaccharides in monocotyledon cell walls that contain glucuronoarabinoxylans.     

浮床黑麦草对城市生活污水氮循环细菌繁衍和脱氮效果的影响

通过设施大棚内容积为1.5m3的人工模拟池试验,研究了浮床黑麦草对模拟城市生活污水氮循环细菌繁衍和脱氮效果的影响。通过研究,阐明浮床植物去除污染水体氮素的可能途径。研究结果表明:浮床黑麦草对模拟城市生活污水总氮和氨氮的去除效果分别达到了31.6%和43.0%;浮床黑麦草根际和根系正下方是各类氮循环细菌生长的最佳区域;浮床黑麦草处理有效地提高了系统氮循环细菌的数量,16d的试验结束时细菌总数(A,单位为CFU.mL-1)达到最大值,其lg(A/(CFU.mL-1))增加至8.82,各类氮循环细菌比对照高3-5个数量级;同时,浮床黑麦草处理显著提高了氮循环细菌的群落多样性,系统内氨化菌、硝化菌、亚硝化菌和反硝化菌共存;明确了浮床黑麦草的吸收同化和氮循环细菌的生物脱氮是浮床黑麦草净化水质的两个重要途径。     

模拟酸雨对农作物生长和产量影响的初步研究

 本文报道了模拟酸雨对小麦、水稻、大豆和白菜的生长与产量影响的试验。模拟酸雨含自然酸雨中已知的离子成分。模拟酸雨PH值为5.6、4.5、4.0、3.5、3.0、2.5和2.0。结果指出：大豆和白菜叶片的可见伤害阈值为pH2.5,水稻和小麦的可见伤害阈值分别为pH2.0和pH3.0,大豆和白菜的电导度随酸雨的pH值下降而增加,pH3.5的模拟酸雨可引起白菜叶片叶绿素含量减少,叶绿素a／叶绿素b的比值发生变化;pH3.0的模拟酸雨使大豆和小麦叶片叶绿素含量下降,叶绿素a／叶绿素b比值改变。pH3.5的模拟酸雨就可抑制白菜生长;pH3.0的模拟酸雨对小麦和大豆生长产生抑制．pH3.5的模拟酸雨造成小麦和白菜减产;pH3.0引起大豆产量下降;pH2.5时,对水稻生长和产量没有影响。大麦和大豆减产主要由酸雨引起籽粒重下降而造成的。     

飞机草挥发油的化学组成及其对植物、真菌和昆虫生长的影响

飞机草挥发油对5种植物幼苗生长有显著的抑制作用,受抑制的大小排序为黑麦草＞白菜＞萝卜＞四季豆＞水稻．中等浓度(800mg·L-1)飞机草挥发油对水稻稻温病菌的抑制作用最强,对长春花疫病菌的抑制作用次之,对香蕉枯萎病菌的抑制作用最弱;其抑茵串分别为61．40％、29．27％和14．44％．10-20μl·株^-1的飞机草挥发油对小菜峨和黄曲条跳甲有显著的驱避产卵作用．经GC／MS,飞机草挥发油的化学成分主要是萜类化合物,如反式—石竹烯(16．58％)、δ—杜松烯(15．85％)、α—可巴烯(11．58％)、氧化石竹烯(9．63％)、大根香叶烯(4．96％)和α—Lu草烯(4．32％)。     

Microscopic investigation of changes in histology and digestibility in the rumen of a forage grass and a forage legume during the first growth stage.

An Italian "Dalita" ryegrass (Lolium italicum) and a European lucerne (Medicago sativa) were harvested at 5 different growth stages to determine the anatomical factors limiting their digestibility and in particular the effects of lignification of the tissues. In vitro digestibility, cell wall contents of the whole plant and stem of lucerne and of the whole plant, stem and leaf blade of ryegrass were determined. The rate and the extent of degradation in the rumen of the different tissues were observed by scanning electron microscopy. This degradation occurred very rapidly with the lucerne stems; the xylem of lucerne was the only undegradable tissue whatever the stage. The collenchyma was degraded in the rumen although with acid phloroglucinol it stained positive for the presence of phenolic compounds. Ryegrass stems were digested more slowly than lucerne stems, and the sclerenchyma and xylem of ryegrass were indigestible whatever the stage. The parenchyma located close to the sclerenchyma became indigestible as the cell walls lignified progressively from the third stage. These results contribute to the understanding of the decrease in digestibility over the first growth stage and the variation in rate of digestion of lucerne and ryegrass in the rumen.     

Phytotoxicity Assay to Assess Plant Species for Phytoremediation of Petroleum-Contaminated Soil

A phytotoxicity bioassay was used to select plant species for phytoremediation that were able to germinate and grow in petroleum-contaminated soil from an industrial site in Canada. Perennial ryegrass (Lolium perenne var. “Affinity”) and alfalfa (Medicago sativa L.) were more successful at germination and root growth than were little bluestem (Schizachyrum scoparium) and crown vetch (Coronilla varia). The phytotoxicity assay provides a rapid, efficient mechanism of prescreening potential plant species and eliminating those not able to germinate and establish in soil conditions present at the contaminated site. This bioassay can potentially reduce the number of pot or greenhouse degradation studies that need to be conducted before plant species can be chosen for petroleum phytoremediation.     

Molecular and functional characterization of a cyclophilin with antifungal activity from Chinese cabbage

An antifungal protein that inhibits the growth of filamentous fungal pathogens was isolated from Chinese cabbage (Brassica campestris L. ssp. pekinensis) by affinity chromatography on Affi-gel blue gel and ion exchange chromatography on CM-Sepharose. The N-terminal amino acid sequence of the protein was highly homologous to that of plant cyclophilins and consequently the protein was denoted as C-CyP. To understand the antifungal activity of C-CyP, we isolated a cDNA encoding its gene from a Chinese cabbage leaf cDNA library. The Chinese cabbage genome bears more than one C-CyP gene copy and C-CyP mRNA is highly expressed in all tissues except the seeds. Recombinant C-CyP catalyzed the cis-trans inter-conversion of the Ala-Pro bond of the substrate, which indicates this protein has peptidyl-prolyl cis-trans isomerase activity. It also inhibited the growth of several fungal pathogens.