Search

Decomposition of coarse detritus (e.g., dead organic matter larger than ~1 mm such as leaf litter or animal carcasses) in freshwater ecosystems is well described in terms of mass loss, particularly as rates that compress mass loss into one number (e.g., a first-order decay coefficient, or breakdown rate, “k”); less described are temporal changes in the elemental composition of these materials during decomposition, with important implications for elemental cycling from microbes to ecosystems. This stands in contrast with work in the terrestrial realm, where a focus on detrital elemental cycling has provided a sharper mechanistic understanding of decomposition, especially with specific processes such as immobilization and mineralization. Notably, freshwater ecologists often measure carbon (C), nitrogen (N), and phosphorus (P), and their stoichiometric ratios in decomposing coarse materials, including carcasses, wood, leaf litter, and more, but these measurements remain piecemeal. These detrital nutrients are measurements of the entire detrital–microbial complex and are integrative of numerous processes, especially nutrient immobilization and mineralization, and associated microbial growth and death. Thus, data relevant to an elemental, mechanistically focused decomposition ecology are available in freshwaters, but have not been fully applied to that purpose. We synthesized published detrital nutrient and stoichiometry measurements at a global scale, yielding 4038 observations comprising 810 decomposition time series (i.e., measurements within a defined cohort of decomposing material through time) to build a basis for understanding the temporality of elemental content in freshwater detritus. Specifically, the dataset focuses on temporally and ontogenetically (mass loss) explicit measurements of N, P, and stoichiometry (C:N, C:P, N:P). We also collected ancillary data, including detrital characteristics (e.g., species, lignin content), water physiochemistry, geographic location, incubation system type, and methodological variables (e.g., bag mesh size). These measurements are important to unlocking mechanistic insights into detrital ontogeny (the temporal trajectory of decomposing materials) that can provide a deeper understanding of heterotroph-driven C and nutrient cycling in freshwaters. Moreover, these data can help to bridge aquatic and terrestrial decomposition ecology, across plant or animal origin. By focusing on temporal trajectories of elements, this dataset facilitates cross-ecosystem comparisons of fundamental decomposition controls on elemental fluxes. It provides a strong starting point (e.g., via modeling efforts) for comparing processes such as immobilization and mineralization that are understudied in freshwaters. Time series from decomposing leaf litter, particularly in streams, are common in the dataset, but we also synthesized ontogenies of animal-based detritus, which tend to decompose rapidly compared with plant-based detritus that contains high concentrations of structural compounds such as lignin and cellulose. Although animal-based data were rare, comprising only three time series, their inclusion in this dataset underscores the opportunities to develop an understanding of decomposition that encompasses all detrital types, from carrion to leaf litter. There are no copyright or proprietary restrictions on the dataset; please cite this data paper when reusing these materials.

Objective Our objective was to evaluate the effects of grazing method on beef cattle performance, residue characteristics, and subsequent corn grain yields. Materials and Methods This was a 3-yr study in which strip-grazing (SG), continuous grazing (CG), and ungrazed control (CT) treatments were arranged in a randomized complete block design with 3 replications per year on a continuous corn production system in central Illinois. Strip-grazed plots were divided into subplots (1, 2, 3) in which cattle back-grazed. Thirty-six spring-calving, multiparous, Angus cows were used in the first and second year of the study and 42 winter-calving Angus heifers were used in the third year. Cattle grazed for 42 d each year following corn harvest. Results and Discussion Cattle in SG plots were 9.8 kg heavier (P = 0.05) postgrazing compared with those on CG plots but did not differ (P = 0.77) in final BCS, indicating adequate performance was maintained regardless of treatment. The SG and CG plots had increased ADF (P = 0.03) and decreased CP (P Implications and Applications Both grazing methods resulted in acceptable performance. Grazing corn residue did not affect subsequent crop yields; however, strip differences in yield within strip-grazed paddocks warrant further investigation.

[ES] Siguiendo las últimas tendencias en el aprovechamiento de subproductos vegetales enfocadas hacia el cumplimiento de los Objetivos de Desarrollo Sostenible y una economía circular, en este trabajo se desarrollaron films a base de almidón de yuca y glicerol con diferentes proporciones de harina de piel de plátano como residuo vegetal (0 (control), 20, 40, 60 y 80%). De cada film se caracterizó: su humedad, su espesor, su permeabilidad al vapor de agua y sus propiedades mecánicas. Los resultados de las formulaciones mostraron una sinergia entre los materiales empleados, ya que se encontró una mejora en las propiedades fisicoquímicas y funcionales de los films en comparación con films hechos con 100% del residuo vegetal y 100% almidón. Así, los films mezcla presentaron mayor extensibilidad, y una capacidad barrera al vapor de agua similar al film de almidón. Sin embargo, cantidades muy elevadas de residuo (80%) empeoraron de forma remarcable las propiedades mecánicas de los films, ya que predomina el residuo en la fase continua polimérica con peores propiedades., [EN] Following the latest trends in the use of vegetable by-products focused on compliance with the Sustainable Development Goals and a circular economy, in this work films based on cassava starch and glycerol with different proportions of plantain skin flour as vegetable residue were developed (0 (control), 20, 40, 60 and 80%). Each film was characterized: its humidity, its thickness, its permeability to water vapor and its mechanical properties. The results of the formulations showed synergy between the materials used, since an improvement was found in the physicochemical and functional properties of the films compared to films made with 100% vegetable residue and 100% starch. Thus, the mixed films presented greater extensibility, and a barrier capacity to water vapor similar to the starch film. However, very high amounts of residue (80%) significantly worsened the mechanical properties of the films, since the residue predominates in the continuous polymeric phase with worse properties.

Increasing the retention and sequestration of plant residue carbon in agricultural soils by incorporating humic acid is the main focus of this study. This study aims to examine the effect of humic acid addition on the decomposition of plant residues of varying degrees of lability. Respiration experiments were conducted to estimate the ability of humic acid to protect plant derived organic compounds from decomposition. Humic acid reduced mineralization from all added residues and this protection effect followed the lability of the residues: vetch> wheat> oak. This could be attributed to the chemical interaction between different plant-derived organic compounds and the humic acid. Lysine was strongly adsorbed to humic acid and mineralization was reduced by 23% as a result of the strong electrostatic interaction. Applying humic acid with vetch reduced all microbial indices as a result of less substrate availability for miroorganisms. On the other hand, applying humic acid with wheat might have simulated the synthesis of extracellular enzymes and the co-metabolism of humic acid (brimming effect), resulting in an enhanced microbial structure toward a higher fungal population. This study suggests: (1) Applying humic acid to ecosystems that receive labile residues (such as vetch) to reduce mineralization and enhance carbon sequestration (2) Applying less labile residues (such as wheat) in combination with humic acid to recover degraded soils and enhance carbon sequestration.

High levels of weed infestation are among the major reasons for the limited adoption of conservation agriculture techniques by farmers in sub-Saharan Africa. This study investigated the effects of ...

Resumen Objetivo desse trabalho foi avaliar o efeito da variabilidade espacial da distribuição da palha na colheita da soja na emergência de aveia preta em sistema plantio direto. O experimento foi conduzido em uma área agrícola de 2,6 ha, sendo avaliados a quantidade de palha (kg ha-1) de soja distribuida pela colhedora, e o estande final de aveia preta (plantas m-2). Foi empregado um gride amostral de 20 pontos, sendo 10 pontos no centro da colhedora e os outros 10 nas extremidades. Nos pontos no centro da colhedora, a quantidade de palha variou de 6.424 a 12.000 kg ha-1 ( = 8.788 ± 1.669 kg ha-1), já o estande final de plantas de aveia preta variou de 165 a 212 plantas m-2 ( = 191 ± 14 plantas m-2). Nos pontos relativos às extremidades, a quantidade de palha reduziu, variando de 1.697 a 3.394 kg ha-1 ( = 2.448 ± 588 kg ha-1), e estande final de plantas de aveia preta aumentou para 267 a 306 plantas m-2 ( = 285 ± 13 plantas m-2), ou seja, redução de 72,14% na quantidade de palha e um aumento de 49,21% no estande. As variáveis analisadas apresentaram correlação forte, negativa e significativa (r = - 0,887; P ˂ 0,05), desde modo, a colhedora empregada no estudo distribui a palha desuniforme, sendo que esta ação afeta o estande final da aveia preta. Abstract The objective of this work was to evaluate the effect of spatial variability straw distribution on soybean harvest in the emergence of black oats in no-tillage system. The experiment was carried out in an agricultural area of 2.6 ha, being evaluated the amount of soybean straw (kg ha-1) distributed by the harvester, and the final stand of black oats (plants m-2). A 20-point sampling grid was used, 10 points in the center of the harvester and the other 10 at the ends. At the points in the center of the harvester, the amount of straw varied from 6,424 to 12,000 kg ha-1 ( = 8,788 ± 1,669 kg ha-1), while the final stand of black oat plants ranged from 165 to 212 plants m-2 ( = 191 ± 14 plants m-2). In the points related to the ends, the amount of straw reduce to 1,697 to 3,394 kg ha-1 ( = 2,448 ± 588 kg ha-1) and the final stand of black oat increase to 267 to 306 plants m-2 ( = 285 ± 13 plants m-2), that is, a reduction of 72.14% in the amount of straw and an increase of 49.21% in the stand. The variables analyzed showed a strong, negative and significant correlation (r = - 0.887; P ˂ 0.05), therefore, the combine used in this study distributes the uneven straw, and this action affects the final stand of black oats.

The objective of this work was to evaluate the effect of spatial variability straw distribution on soybean harvest in the emergence of black oats in no-tillage system. The experiment was carried out in an agricultural area of ​​2.6 ha, being evaluated the amount of soybean straw (kg ha-1) distributed by the harvester, and the final stand of black oats (plants m-2). A 20-point sampling grid was used, 10 points in the center of the harvester and the other 10 at the ends. At the points in the center of the harvester, the amount of straw varied from 6,424 to 12,000 kg ha-1 ( = 8,788 ± 1,669 kg ha-1), while the final stand of black oat plants ranged from 165 to 212 plants m-2 ( = 191 ± 14 plants m-2). In the points related to the ends, the amount of straw reduce to 1,697 to 3,394 kg ha-1 ( = 2,448 ± 588 kg ha-1) and the final stand of black oat increase to 267 to 306 plants m-2 ( = 285 ± 13 plants m-2), that is, a reduction of 72.14% in the amount of straw and an increase of 49.21% in the stand. The variables analyzed showed a strong, negative and significant correlation (r = - 0.887; P ˂ 0.05), therefore, the combine used in this study distributes the uneven straw, and this action affects the final stand of black oats. Objetivo desse trabalho foi avaliar o efeito da variabilidade espacial da distribuição da palha na colheita da soja na emergência de aveia preta em sistema plantio direto. O experimento foi conduzido em uma área agrícola de 2,6 ha, sendo avaliados a quantidade de palha (kg ha-1) de soja distribuida pela colhedora, e o estande final de aveia preta (plantas m-2). Foi empregado um gride amostral de 20 pontos, sendo 10 pontos no centro da colhedora e os outros 10 nas extremidades. Nos pontos no centro da colhedora, a quantidade de palha variou de 6.424 a 12.000 kg ha-1 ( = 8.788 ± 1.669 kg ha-1), já o estande final de plantas de aveia preta variou de 165 a 212 plantas m-2 ( = 191 ± 14 plantas m-2). Nos pontos relativos às extremidades, a quantidade de palha reduziu, variando de 1.697 a 3.394 kg ha-1 ( = 2.448 ± 588 kg ha-1), e estande final de plantas de aveia preta aumentou para 267 a 306 plantas m-2 ( = 285 ± 13 plantas m-2), ou seja, redução de 72,14% na quantidade de palha e um aumento de 49,21% no estande. As variáveis analisadas apresentaram correlação forte, negativa e significativa (r = - 0,887; P ˂ 0,05), desde modo, a colhedora empregada no estudo distribui a palha desuniforme, sendo que esta ação afeta o estande final da aveia preta.

Although most research demonstrates the importance of green manure, some aspects have yet to be elucidated. Thus, the present study aimed to determine the biomass decomposition pattern of plants used as green manure in dystrophic Yellow Latosol (coastal caatinga phase), under a dry megathermal climate, with a small water surplus. A completely randomized design was used, with nineteen treatments and four repetitions. The decomposition constant (k), remaining dry biomass and half-life (T1/2) of the residue after 120 days in the field were assessed. Cowpea, jack bean and sunflower (cv. Catissol and IAC Uruguai) are rapidly decomposing species with a half-life ranging from 98 to 112 days to decompose 50% of biomass. Dwarf pigeon pea, crotalária juncea, sorghum 1 and siratro are slow-decomposing species, with a 315 to 630-day half-life to decompose 50% of biomass. Both groups are recommended for intercropping because the decomposition rate of their plant residue is compatible with soil protection and nutrient supply, in addition to being sync with the nutrient requirements of cash crops. = Embora a maioria dos estudos evidencie a importância da adubação verde, existem aspectos ainda carentes de respostas por parte das pesquisas. Assim, objetivou-se com o presente trabalho determinar o padrão de decomposição da biomassa de plantas utilizadas como adubos verdes em Latossolo Amarelo distrófico, fase caatinga litorânea, sob influência de clima subúmido seco, megatérmico, com pequeno excedente hídrico. O delineamento empregado foi o inteiramente casualizado, com quatro repetições e dezenove tratamentos. Avaliaram-se: constante de decomposição (k), quantidade de biomassa seca remanescente e tempo de meia vida (T1/2) dos resíduos após 120 dias de permanência no campo. Feijão-caupi, feijão-de-porco, girassol Catissol e girassol IAC Uruguai compõem o grupo das espécies de decomposição rápida, com tempo de meia-vida variando de 98 a 112 dias para decompor 50% da biomassa. Guandu-anão, crotalária juncea, sorgo 1 e siratro compõem o grupo das espécies de decomposição lenta, com tempo de meia-vida alto, variando de 315 a 630 dias para decompor 50% da biomassa. Esses dois grupos podem ser recomendados em cultivo consorciado, pois podem propiciar velocidade de decomposição dos resíduos compatível com a proteção do solo e com o fornecimento de nutrientes em sincronia com a demanda das culturas comerciais.

Recently, the use of biochars for stabilization of soil heavy metals has been expanded due to their adsorption characteristics, low cost and carbon storage potential. A factorial experiment was per...

Utilizing the proper techniques of plant residue composting can play a significant role in reducing the adverse environmental impacts of chemical fertilizers. Herein the effects of commerci...

A continuous rise in the global demand for palm oil has resulted in the large‐scale expansion of oil palm plantations and generated environmental controversy. Efforts to increase the sustainability of oil palm cultivation include the recycling of oil mill and pruning residues in the field, but this may increase soil methane (CH4) emissions. This study reports the results of yearlong field‐based measurements of soil nitrous oxide (N2O) and CH4 emissions from commercial plantations in North Sumatra, Indonesia. One experiment investigated the effects of soil‐water saturation on N2O and CH4 emissions from inorganic fertilizers and organic amendments by simulating 25 mm rainfall per day for 21 days. Three additional experiments focused on emissions from (a) inorganic fertilizer (urea), (b) combination of enriched mulch with urea and (c) organic amendments (empty fruit bunches, enriched mulch and pruned oil palm fronds) applied in different doses and spatial layouts (placed in inter‐row zones, piles, patches or bands) for a full year. The higher dose of urea led to a significantly higher N2O emissions with the emission factors ranging from 2.4% to 2.7% in the long‐term experiment, which is considerably higher than the IPCC standard of 1%. Organic amendments were a significant source of both N2O and CH4 emissions, but N2O emissions from organic amendments were 66%–86% lower than those from inorganic fertilizers. Organic amendments applied in piles emitted 63% and 71% more N2O and CH4, respectively, than when spread out. With twice the dose of organic amendments, cumulative emissions were up to three times greater. The (simulated) rainwater experiment showed that the increase in precipitation led to a significant increase in N2O emissions significantly, suggesting that the time of fertilization is a critical management option for reducing emissions. The results from this study could therefore help guide residue and nutrient management practices to reduce emissions while ensuring better nutrient recycling for sustainable oil palm production systems.

Biocementation of hazardous waste is used in reducing the mobility of contaminants, but studies on evaluating its efficacy have not been well documented. Therefore, to evaluate the efficacy of this method, physicochemical factors affecting stabilized hazardous products of in situ microbially induced calcium carbonate precipitation (MICP) were determined. The strength and leach resistance were investigated using the bacterium Pararhodobacter sp. Pb-contaminated kiln slag (KS) and leach plant residue (LPR) collected from Kabwe, Zambia, were investigated. Biocemented KS and KS/LPR had leachate Pb concentrations below the detection limit of

The commonly used subsoiling cum rotary tiller machine (SRT) in Northern China is a combination of subsoiler and horizontal rotary tiller, however backfilling of the subsoiling slot, excessive vibration and plant residue wrapping on rotary components has been rarely considered. Therefore, the rotary components and assembly were redesigned to address these issues and to an SRT fitted with IT225 short curve rotary blades behind the V-shape subsoiling slots and IIT245 long curve rotary blades between the tines. Long and short blades were fitted on a rotor in a double helix, with optimal spiral angles of 65o and 90o, and phase angle of 147o and 180o, respectively. Compared with the commonly used SRT (CSRT), the additional anti-wrapping cutting blades in the circumferential and axial direction of ASRT could remove hanging residue on the blade holders, wrapping on the rotor and formation of an isolation layer. Moreover, the cutting edge curve of anti-wrapping cutting blades was an exponential curve. Field tests demonstrated that the redesigned SRT with anti-vibrating and anti-wrapping rotary components (ASRT) had was a significant advancement over the CSRT. Moreover, the working depth of rotary tillage was more stable, while other observations confirmed that backfilling of the subsoiling slot was also improved. Keywords: subsoiling, rotary tiller, anti-vibration, anti-wrapping, backfill, tillage DOI: 10.25165/j.ijabe.20191204.4369 Citation: Zheng K, McHugh A D, Li H W, Wang Q J, Lu C Y, Hu H N, et al. Design and experiment of anti-vibrating and anti-wrapping rotary components for subsoiler cum rotary tiller. Int J Agric & Biol Eng, 2019; 12(4): 47–55.

A 5-year field study was conducted on the effect of plant residue management on soil erosion, runoff, bulk density, penetration resistance, and organic carbon. There were three treatments: burning residues on field (BR), returning residues unto the soil surface after harvesting (TR), and removing residues from soil surface (RR) (control treatment). At the end of the 5-year treatment, a rainfall simulation at 90 mm h−1 was applied to each plot. After rainfall simulation started, the runoff volume and soil loss amount in samples were collected at four sampling times. The results showed that the runoff volume for BR (from 145.5 ± 12.2 to 190.0 ± 11.8 mL) differed significantly (p ≤ 0.01) from that of RR (from 32.3 ± 5.5 to 67.5 ± 11.1 mL) and TR (from 10.0 ± 0.7 to 16.7 ± 3.3 mL). A significant difference (p ≤ 0.01) was also observed between RR and TR regarding runoff volume and soil loss amount in different sampling times, except for the first sampling time (2–4 min). The runoff volume in BR and TR ...

Flood increases due to an increase in river overflow which affects on abiotic and biotic factors. The preliminary study of flood-affected crops was carried out in flood-affected cropland of Koshi Tappu Region of Eastern Nepal. For the experiment the plant residues of Eichhornia crassipes and Sesbania rostrata and inorganic fertilizer were selected to examine the growth and yield in Vigna unguiculata. The appropriate treatments for the production of V. unguiculata were analyzed. Before applying treatments, soil was collected and analyzed for physicochemical, microbial biomass and available nitrogen. Soil texture, soil moisture, water holding capacity and bulk density (BD) were calculated. The parameters such as soil pH organic carbon, organic matter and total nitrogen were determined. Soil microbe increases the significance of organic carbon and soil nitrogen is correlated for growth and yield. The results showed that the combined urea and plant residue increases the highest yield. And the Eichhornia compost represents the highest leaf area index and biomass. The total pod production was found in the Echhhornia compost. The dry weight per single pod in Eichhornia fresh was 7.82 g and in Sesbania fresh was 7.42 g. It proves that the land pattern is significant for the soil organic compounds. The experiment showed that the use of plant residues enhanced the increase of physicochemical properties of soil by adding the nutrients. The combined Urea + Eichhornia supports the best growth and development of the plant.

Soils play a major role in the global carbon cycle and are crucial to the management of climate change. Changes in plant cover derived from different agricultural practices induce variations in the quality of plant residue inputs and in the soil microbial community structure and activity, which may enhance the storage and protection of organic carbon (OC) and nitrogen (N) within aggregates. The aim of this study was to assess how differences in the chemical composition of plant residues in combination with tillage management practices affect the local microbial community activity and structure, and subsequent soil aggregation and OC and N dynamics in an organic, rainfed almond (Prunus dulcis Mill.) orchard. In the laboratory, three types of plant residue (shoots, roots, and the combination of both) coming from different species belonging to each agricultural practice (reduced tillage, reduced tillage plus green manure, reduced tillage plus organic manure, and no-tillage) were mixed with their respective soils and the CO released was measured over 243 days at 60% WHC and 28 °C. Water-stable aggregates (including microaggregates within macroaggregates), enzymatic activities related to carbon (dehydrogenase and β-glucosidase) and N (urease) cycling, and the microbial biomass and community structure through phospholipid fatty acid analysis, were measured at the end of the incubation period. Our results indicate that the chemical composition of plant residues controls the microbial community response, mediating decomposition and the incorporation of OC and N in stable aggregates. Therefore, the incorporation of labile and N-rich plant residues into the soil by reduced tillage is recommended since mixing roots and shoots from green manure increased the formation of free micro-aggregates and improved OC and N stabilization in our semiarid agroecosystem., This research was supported with funds from the Fundación Séneca of the Murcia Region (projects 08757/PI/08, EMISEMUR 19350/PI/14 and DECADE 20917/PI/18). Parts of this research were performed within the framework of the project IMPASEC AGL2011-25069 funded by the Spanish Ministerio de Economía y Competitividad. María Almagro was supported by the Juan de la Cierva Program (Grant IJCI-2015-23500) and Antonio Ruiz-Navarro by the Fundación General from the Spanish Research Council (CSIC, ConFuturo Progamme).

One of the most ancient fibre is flax fibre, found in different archaeological studies and documented in history. It is supposed to be the oldest natural plant fibre found in different parts of the globe. It is a seasonal crop normally grown in different parts of Europe, America and Asian countries. This chapter covers the overall aspects of flax textile starting from cultivation to end product, disposability, and different sustainability steps involved in the value chain of flax. Apart from these, applications of different components of flax biomass and plant residue in some other areas like medicinal, industrial, etc. for diversification have been discussed. Further, the chapter focuses on minimum use of artificial resources (man-made products) for making the product and process environmental-friendly and sustainable.

Pšenična trava mladi su izdanci pšenice (Triticum aestivum L.) koji se u ljudskoj i životinjskoj prehrani najčešće konzumiraju kao sok, prah te tablete. Sadrži preko 100 elemenata koji su neophodni čovjeku kao što su esencijalne masne kiseline, enzimi i antioksidansi. Izvor je klorofila, vitamina (A, B, B17, C, E, F i K), minerala (željezo, kalij, kalcij i magnezij) te za razliku od zrna pšenice ne sadrži gluten. Zbog svoje nutritivne vrijednosti sok pšenične trave postao je najpopularniji sok mladice na svijetu. Cilj ovog istraživanja bio je utvrditi razlike u sadržaju ukupnih klorofila, karotenoida, fenola i vitamina C u soku i biljnom ostatku koji je ostao nakon cijeđenja soka te razlike između deset sorti pšenične trave. U prosijeku za sva provedena ispitivanja utvrđeno je kako biljni ostatak sadrži više ukupnih klorofila, karotenoida i vitamina C u odnosu na sok, ali je u soku utvrđen veći sadržaj fenola s pragom značajnosti od 95 % te 99 %. Također je utvrđena značajna razlika u sadržaju ukupnih klorofila, karotenoida, fenola i vitamina C kod deset sorti pšenične trave s pragom značajnosti od 95 %. Najbolje rezultate pokazale su sorte Ružica u soku te Divana u biljnom ostatku, a najlošije rezultate imale su sorte Felix u soku te Ludwig u biljnom ostatku. Prema rezultatima provedenog istraživanja može se zaključiti kako bi najbolje bilo za kućnu upotrebu konzumirati cjelovite svježe listove pšenične trave, sorti Ružica i Divana, kako bi se najbolje iskoristio potencijal koji ova nutritivno vrijedna biljka ima., Wheatgrass are young shoots of wheat (Triticum aestivum L.) that are most often consumed in human and animal nutrition as juice, powder and tablets. It contains over 100 elements that are essential to human such as essential fatty acids, enzymes and antioxidants. It is a source of chlorophyll, vitamins (A, B, B17, C, E, F and K), minerals (iron, potassium, calcium and magnesium) and unlike wheat grain it does not contain gluten. Due to its nutritional value, wheatgrass juice has become the most popular shoot juice in the world. The aim of this study was to determine the differences in the content of total chlorophyll, carotenoids, phenols and vitamin C in the juice and plant residue left after squeezing the juice and the differences between the ten varieties of wheat grass. On average, for all tests performed, the plant residue was found to contain more total chlorophyll, carotenoids and vitamin C than the juice, but the juice contained a higher phenol content with a significance threshold of 95 % and 99 %. Also, a significant difference in the content of total chlorophyll, carotenoids, phenols and vitamin C was found in ten different varieties of wheat grass with a significance threshold of 95 %. The varieties Ruzica in juice and Divana in plant residue showed the best results in all tests, and the varieties Felix in juice and Ludwig in plant residue had the worst results. According to the results of the research, it can be concluded that it would be best to consume whole fresh leaves of wheat grass, varieties Ruzica and Divana for home use, in order to best use the potential that this nutritionally valuable plant has.

Most crops can be successfully grown using conservation planting technology. There has been resistance in using conservation tillage planting methods for peanut as many specialists from past years promoted deep plowing to bury plant residue that might carry various disease organisms. This document will help guide growers who want to use conservation tillage in making that change.https://edis.ifas.ufl.edu/ag187

Background Foliage residue decline data are used to refine the risk assessment for herbivorous birds and mammals foraging in fields treated with plant protection products. For evaluation, current EFSA guidance has a clear focus on single-first order (SFO) kinetic models. However, other kinetic models are well established in other areas of environmental risk evaluations (e.g., soil residue assessment), and easy-to-use calculation tools have become available now. We provide case studies with 6 fungicides how such evaluations can be conducted with two of these tools (KinGUII and TREC) that have been developed by Bayer. Results SFO kinetics provided the best fits only for 13 of 36 residue decline studies conducted in a standardized design under field conditions. Biphasic models (double first order in parallel, hockey stick) were often superior and sometimes more conservative for risk assessment. The additional effort is manageable when using software such as KinGUII and TREC, and appears justified by the more reliable outcome of the evaluations. Conclusions Further research would be useful to better assess the extent to which non-SFO better fits foliage residue decline, but our study suggests that it may be a significant proportion. Therefore, we encourage the use of biphasic models in the regulatory risk assessment for herbivorous birds and mammals, in the ongoing revision of the European Food Safety Authority (EFSA) guidance document from 2009.

Zinc plant residue (55.59% zinc content, 0.132% cobalt content) contains a variety of valuable metals, including cobalt, and its abundance is even higher than the abundance of some cobalt ores. In this study, the main influencing factors for the separation of zinc and cobalt by alkali leaching were studied, including sodium hydroxide concentration, reaction temperature, reaction time, solid–liquid ratio (A/S), agitation speed, etc. With an optimal condition of sodium hydroxide concentration 2.5 mol/L, liquid–solid ratio 20/1 (mL/g), reaction time 40 min, reaction temperature 30 °C, zinc leaching rate reached 96.33%, and cobalt leaching rate is less than 10%, the purpose of the separation of cobalt and zinc was initially achieved.

Present work focuses on recovery of lead from a zinc plant residue (ZPR) in alkaline media. Firstly, Zn and Pb were selectively extracted in NaOH from ZPR containing 56.9% Pb, 0.34% Ag, 3.93% Zn, and 0.88% Cu. Lead was effectively leached in a two-step process. The leach-I solubilized 39.5% Pb and 58.5% Zn in 2.0 M NaOH at 25 ℃ and 10% pulp density in 30 min. Subsequent leaching in 3.0 M NaOH yielded overall extraction of >99% Pb and 67% Zn with stage efficiency of 59.5% Pb and 8.5% Zn. Above 99.9% Pb was recovered from the leach liquor in 30 min at 25 ℃ and Zn: Pb mole ratio = 1.2:1.0 by cementation using Zn powder. Interestingly silver in the final residue was enriched from 0.3% to 1.17% making it a promising resource of Ag.

Dental calculus from archaeological samples is a rich source of ancient biomolecules, such as DNA, proteins, and microremains, mainly related to food. Focusing on different contents, laboratory procedures require specific treatments that necessitate the same material and are generally mutually exclusive; therefore, the low quantity of the starting material is often the main limiting factor for gathering data. Here, we compare different combinations of laboratory procedures in order to identify the best strategy for simultaneously extracting DNA and isolating plant residue. Preliminary tests were performed on fresh plant materials to verify the effects of the DNA extraction protocols on starch grains and phytoliths. Different combined experimental procedures were successively applied to the dental calculus of three medieval individuals. Our results confirmed that authentic genetic data could be recovered from ancient dental calculus using protocols commonly used for extracting DNA from ancient bones and teeth, and the residual pellet could be successfully used for morphological characterization of plant residues. In addition, we confirmed that, although most DNA within calculus is microbial, the whole human mitochondrial genome could be reconstructed using target enrichment techniques.

This study investigated the adsorption behavior of selected heavy metals (Pb, Cu, and Ni) under single and multi-metal conditions by a light textured calcareous soil amended with plant residue bioc...

Mulching in smallholder conservation agriculture (CA) systems is constrained by lack of adequate crop residues. A three-year study assessed the effects of reduced tillage systems combined with diff...

Microbial biomass plays a critical role in soil organic carbon (SOC) mineralization. However, the effects of microbial biomass size on SOC mineralization are poorly understood. We investigated how the priming effect (PE) of plant residue inputs on native SOC mineralization responds to changes in microbial biomass size and nitrogen (N) availability in the same soil with a 23 y history of crops and grass cover with contrasting SOC contents. The size of the soil microbial biomass was changed by pre-incubating soils with glucose. The pre-incubated soils were then treated with 13C-labeled ryegrass residue combined with or without N to determine the PE. In all soils, the addition of ryegrass residue significantly increased cumulative carbon dioxide (CO2) production, whereas the addition of N decreased it compared to the control (no ryegrass or N addition). After a 42-day incubation, only 9–16% of the ryegrass carbon (C) was mineralized to CO2, which contributed approximately 55 and 34% to the total CO2 production in crop and grass soils, respectively. The addition of N decreased CO2 production during the ryegrass decomposition by 9–45%, while the change in soil microbial biomass size had no impact. In addition, a positive PE was generally found in the soils amended with ryegrass alone, while the application of ryegrass residue combined with N decreased the PE. Moreover, the priming effect was independent of the size of the microbial biomass in crop soil. However, we observed a significant interaction of microbial biomass size and N availability on the priming effect in a grass soil but not in a crop soil. Our results indicate that soil microbial biomass size and soil C influence the magnitude and direction of the priming effect from C inputs depending on N availability.

Removing plant residue from soil has been shown to have an adverse effect on soil health; however, the addition of cover crops may help mitigate these impacts. This study was conducted to assess the effect of incorporating cover crops on soil health with varying removal rates of corn (Zea mays L.) residues. Corn was grown in rotation with soybean (Glycine max) in a randomized, split-block design with three different corn residue removal levels (37, 55, and 98% of total above-ground C) as whole plot treatments and the presence or absence of cover crops as the split plot treatment. Soil samples were collected from both crop phases following 7 years of cover crop treatment and subjected to a suite of soil health measurements. In the soybean phase immediately following corn residue removal, there were significant (P = 0.025) increases in the erodible fraction (EF) of soil aggregates and reductions in the stable, larger aggregate fractions. Cover crops mitigated these changes in aggregate distributions in the highest residue removal treatment. Residue removal resulted in a significant decrease in fPOM (P = 0.03) while the addition of cover crops increased fPOM levels during the soybean phase (P = 0.002). Residue removal significantly (P = 0.017) decreased soil microbial enzyme activities while cover crops restored activities in the highest residue removal treatment (P = 0.037). We also found higher fungal:bacterial ratios with cover cropping compared to no cover crops. We conclude that cover cropping continued over multiple years can partially mitigate negative effects of crop residue removal on soil health thus limiting soil erosion and maintaining nutrient cycling activities in the vulnerable period following residue removal.

An attempt was made to recycle waste biomass and mineral powder (waste mica) as an alternative source of potassium (K) through composting technology. Two different waste biomass, isabgol straw and palmarosa distillation waste along with two levels of waste mica (2 and 4% as K) were used for preparation of enriched composts. A notable decrease of C:N ratio was observed at the end of the composting (150 days) as an indicator of compost maturity. The mature composts were evaluated for K-supplying capacity through laboratory leaching and soil incubation study. Significantly higher water-soluble K released initially followed by a sharp decrease up to 21 days of leaching thereafter gradually decreased up to 35 days of leaching. Water-soluble K was released from K-enriched (mica charged) compost significantly higher than the ordinary compost throughout the leaching period. Soil incubation study also revealed that application of K-enriched compost greatly improved the available K (water soluble and exchangeable) pools in K-deficient soil which indicated that a considerable amount of K releases during composting. Therefore, K-enriched compost could be an effective alternative of costly commercial K fertilizer and eco-friendly approach to utilize low-cost waste mineral powder and plant residue.

Soil microbial communities and their related characteristics are an important agent for soil fertility, productivity, and sustainability. Also, they are useful indicators of soil quality and life index in agricultural systems. The objectives of this study were the effect of nanozeolite and plant residues on soil microbial communities and their characteristics and also, the assessment of incubation timing on soil microbial properties. Soil microorganisms are very important in the decomposition of plant residues. I n this regard, the soil samples were treated by nanozeolite (0, 10 and 30% Weight), Alfalfa and wheat straw (0 and 5% Weight). The treated soil samples were incubated in lab condition for 90 days. The result of this study showed that Bacterial, Fungal, and Actinomycete populations increased by the addition of 30% of nanozeolite and 5% of plant residues, especially alfalfa straw. Also, the addition of nanozeolite and plant residues treatments improved MBC, BR, and SIR as microbial characteristics. These parameters increased after 30 days of starting incubation, then decreased until the 75 th day and finally increased slightly on the 90 th day. In fact, the addition of nanozeolite and plant residues into the soil had positive effects on improvement of carbon pools and increasing carbon sequestration in it. Applied nanozeolite and plant residues in soil, improved carbon pools and increased carbon sequestration in soil. Also the application of nanozeolite and plant residues especially alfalfa straw had positive effects on improvement of soil biological communities and characteristics.

Interactions of clay minerals with organic materials and the consequences of these interactions on dynamics of organic carbon (OC) have been reviewed in detail. However, the effects of exchangeable cations and clay types on the turnover rate of OC have not been given much attention. Appropriate amounts of homoionic Na-, Ca- and Al-clays from Georgia kaolinite, Illinois illite and Wyoming bentonite were mixed with pure sand to prepare artificial soils with different clay contents, exchange cations and clay types. Alfalfa plant residues were incorporated into the artificial soils and the soils were inoculated with microbes from a natural soil and incubated for 184 days to study the effects of clay contents, exchangeable cations and clay types on the mineralization of OC and plant residue derived microbial biomass. Mineralization of plant residue carbon was significantly ( ⁎⁎ p ⁎⁎ p ⁎⁎ p

The accumulation of NO3− in the soil has resulted in increased nitrogen (N) loss through runoff, leaching, and gaseous emissions. Microbial immobilization of NO3− as an important process in reducing soil NO3− accumulation has been for a long time neglected due to the predominant viewpoint that microbes preferentially immobilize NH4+-N. Microbial NO3− immobilization is generally carbon (C)-limited, and thus exogenous organic C input may enhance microbial NO3− immobilization. However, the effect of the quality and quantity of exogenous organic C input on soil microbial NO3− immobilization is poorly understood, and a synthetic assessment on such an effect is lacking. We thus assessed the impact of exogenous organic C type, the application rate of simple organic C (glucose and acetate), complex organic C type (animal manure, plant residue) and the C/N ratio of complex organic C on soil microbial NO3− immobilization rate using a meta-analysis. We found that the quality and quantity of exogenous C input affect soil microbial NO3− immobilization: microbial NO3− immobilization was enhanced with the addition of simple organic C at rates >500 mg C kg−1, or complex organic C with C/N ratios >18. Furthermore, a positive relationship between the natural log of response ratio of soil microbial NO3− and NH4+ immobilization indicates the simultaneous utilization of NH4+ and NO3− under elevated C availability. We conclude that specific exogenous organic C input at a high rate or with a high C/N ratio can enhance microbial NO3− immobilization and reduce soil NO3− accumulation.

Nitrogen fertilization may affect the decomposition of soil organic matter (SOM) and plant residues in soil, but this effect is still very uncertain and depends on living plants. We investigated the effects of mineral N (Nmin) availability on SOM and plant residue decomposition in wheat (Triticum aestivum L.) growing soils in a pot experiment. Five treatments were assessed: (1) Control [no maize (Zea Mays L.) residues and no N fertilization]; (2) 15N-urea addition; (3) 15N maize leaves; (4) 15N maize leaves + urea; and (5) 15N-urea + maize straw. The decomposition of SOM and plant residues was traced by the changes of N and C in the light fraction (density

Temperature sensitivity of organic carbon (C) mineralization is affected by C inputs, but predicting the magnitude of the response remains a challenge. We investigated how temperature and exogenous C inputs affected the apparent organic C mineralization in soils with a range of soil organic C (SOC) contents. Soils with 2.9, 4.0, and 6.8% SOC content were incubated with or without C sources (either plant residues or glucose), at two temperatures (15 or 25 °C) for 120 days. Apparent organic C mineralization was significantly affected by SOC content and C inputs. Cumulative CO 2 production in soils with a higher SOC content was less sensitive to C inputs. Glucose was always more effective in stimulating CO 2 production than plant residue. Without exogenous C inputs, the temperature sensitivity of organic C mineralization (described by Q 10 value) was higher in the 4.0% SOC soil (2.31) than in the 2.9% (1.12) and 6.8% SOC soils (1.30). The addition of exogenous C decreased Q 10 values by up to 131% in the 4.0% SOC soil, which was not observed in other two soils. In general, C inputs increased the Q 10 of the estimated active ( C a ) and stable C ( C s ) pools in all the tested soils, especially the C s pool in the 4.0 and 6.8% SOC soils. Results indicated that the effect of C inputs on apparent organic C mineralization (either stimulatory or inhibitory) is influenced by SOC content and C source, and that temperature sensitivity of organic C mineralization in the presence of exogenous C is highly sensitive to SOC content.

Poor infrastructure in developing countries, combined with challenging geographical characteristics, is associated with problems of limited access to resources, poor transportation and environmental health issues. In some developing countries, there are no heating systems during the winter season, which causes problems for both people and livestock. The most common heating source is from open fires using biomass from animal and plant residue, which are also used for cooking. Fireplaces are typically located inside the house, which can lead to respiratory health problems because of limited ventilation. Thus, heating systems with proper ventilation are desirable to mitigate health problems and improve living conditions. Here we describe the application of ‘Ondol’, a traditional Korean heating system that was redesigned for improved efficiency, in remote villages in a mountainous region of Nepal. Total 10 models of Ondol were designed and fabricated, and the temperature profile and uniformity were characterized to select the optimal design. The height and type of the ‘Gorae’ were the most important factors in determining the efficiency. The optimal design was provided to local people, who were trained to replicate and build the Ondol on their own. A post-installation survey was carried out to evaluate the effectiveness of the system.

The analysis of residues on stone tools can yield important insights into the tool-using behaviors of Paleolithic hominins. The ambiguity of residue identifications using visible-light microscopy (VLM) has led to the development of additional techniques for their characterization. Reflectance-based Fourier-transform infrared microspectroscopy (FTIRM) is a technique with great potential to aid in non-destructive residue identifications. Recent applications of the technique, however, have been hampered by methodological challenges, causing the infrared signals to be dominated by the stone rather than the residues. We address this problem by systematically testing the limits of FTIRM on five categories of experimental plant residues (wood bark, wood pith, grass leaves, starch, and resin). We demonstrate that it is possible to obtain FTIRM spectra of in situ plant residues wherein the effect of the stone is virtually eliminated. We also generate reflectance FTIRM spectral standards for each plant residue investigated and provide peak assignments for the major peaks in all spectra. The sensitivity of the technique means that slight differences in sample preparation can result in spectral differences as well. This means that archaeological application of the technique will require (1) careful, peak-by-peak analyses of the results, (2) extensive spectral libraries, and (3) research into the effects of decomposition.

Made available in DSpace on 2018-11-12T17:27:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-12-01. Added 1 bitstream(s) on 2021-07-14T17:51:23Z : No. of bitstreams: 1 S1806-66902016000400649.pdf: 55791 bytes, checksum: 77a3afe368f0db051971353798b413a4 (MD5) RESUMO A escolha correta das culturas para cobertura do solo melhora a sustentabilidade do sistema de cultivo, pois pode potencializar o uso dos herbicidas, reduzir a infestação de plantas daninhas e melhorar o desempenho das culturas. Com o objetivo de estudar o efeito de coberturas mortas de inverno e do uso de herbicidas sobre comunidade de plantas daninhas na cultura do milho, foi realizado um estudo no delineamento inteiramente casualizado com os tratamentos dispostos em parcelas subdivididas, com quatro repetições. As parcelas, em número de seis, foram compostas pelas seguintes culturas de inverno: Lupinus albus, Lathyrus sativos, Triticum aestivum, Avena strigosa, Raphanus sativus, mais uma testemunha mantida em pousio. As subparcelas em número de três, foram compostas por: 1 - pulverização apenas de herbicida de manejo antes da semeadura do milho; 2 - herbicida de manejo após a semeadura do milho + herbicida residual, e 3 - testemunha sem aplicação de herbicidas. As coberturas mortas de aveia-preta e nabo-forrageiro proporcionam as menores densidades de plantas daninhas e acúmulos de massa seca da comunidade infestante, independente da aplicação ou não de herbicidas. Houve uma maior germinação de B. pilosa nas parcelas mantidas com a cobertura de tremoço, com exceção das subparcelas onde se aplicou herbicida em pré-emergência, o que evidencia um efeito estimulante da cobertura morta. O emprego de algumas espécies na formação da cobertura morta para o plantio direto pode dispensar ou reduzir a quantidade de herbicidas necessária para o controle das plantas daninhas. ABSTRACT The correct choice of cover crops improves the sustainability of a farming system, as it can enhance the use of herbicides, reduce weed infestation and improve crop performance. With the aim of studying the effect of winter mulches and the use of herbicides on a community of weeds in maize, a study was carried out in a completely randomised design where the treatments were arranged in a scheme of split lots with four replications. The lots, six in number, comprised the following winter crops: Lupinus albus, sativos Lathyrus, Triticum aestivum, Avena strigosa, Raphanus sativus, and a control kept fallow. The three sub-lots comprised, 1 - spraying the management herbicide before sowing the maize, 2 - management herbicide after sowing the maize + residual herbicide, and 3 - control without the application of herbicide. Mulches of black oat and forage turnip gave the lowest weed densities and accumulations of dry weight in the weed community, irrespective of the application of herbicide. There was greater germination of B. pilosa in the lots maintained with a cover of lupins, with the exception of those sub-lots where herbicide was applied pre-emergence, demonstrating the stimulating effect of mulch. The use of certain species in the formation of mulch under direct planting can dispense with or reduce the amount of herbicides needed for weed control. Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal

4 pages; International audience; Applying composts is useful for increasing soil carbon (C) stocks and improving agricultural productivity. In order to understand the effects of composts on soil organic matter (SOM) formation and mineralisation, 13C-labelled plant residues, previously composted or not, were incubated in an arable soil. The amount of 13C was quantified in the CO2 evolved, the dissolved organic carbon (DOC) and in the microbial biomass (MB). Composting decreased (from 29 to 9%) the proportion of the plant residue labile pool and increased the residence time of both labile and more stable pools from 21 to 34 days and 1.5–5.5 years, respectively. At the beginning of the incubation, the amounts of 13C in the DOC and MB were significantly higher when adding fresh residues than composted ones to the soil. A priming effect on SOM mineralisation (+21% over 3 years) was only observed for non-composted residues. These differences were attributed to changes in the chemical composition of plant materials during composting (less sugars and lipids, more lignins). In terms of C budget, the total loss of CO2 (including the composting process and the SOM priming by fresh residues) was comparable for both treatments after 600 days of incubation.

Through field experiments and empirical analysis methods, this study determined the dependence of plant residue removal on the row cleaner’s settings in strip-tillage. The main research object of this study is row cleaners. By changing the slip angles (10, 15, and 22.5°), the gap between row cleaner discs in parallel (165, 180, and 195 mm), and the driving speed (1.3, 1.9, 2.5, and 3.1 m s−1), we determined what percentage of wheat residue was removed from the strip on the surface of the soil and what distance it was moved. The percentage of removed plant residue was determined by evaluating the differences between the masses of the plant residue taken from non-removed and removed strips. Empirical analysis of the results of the field experiments showed that both the amount of the removed plant residue and the distance it is moved to were the best when the slip angle was 15°, the gap between the discs of row cleaner was 180 mm, and the driving speed was 2.5 m s−1. With these parameters, up to three-quarters of the plant residue was removed from the soil surface of the strip, which was relocated 308 mm from the middle of the strip. If the slip angle and the driving speed are increased further, even more plant residue can be removed; however, if the plant residue is relocated too far away, it may fall into the zone of the adjacent strip.

The interactive effects of the types and contents of soil clay fractions (SCFs) and plant-residue addition rates on soil organic carbon (SOC) stabilisation are largely unknown. We conducted incubation experiments by amending a sandy soil sample with kaolinitic-illitic, smectitic and allophanic SCFs and adding wheat residues to the mineral mixtures to compare their C stabilisation capacity. The rate of carbon (C) decomposition was higher in the kaolinitic-illitic SCF followed by smectitic and allophanic clay minerals. The supply of easily degradable C substrate from decomposing residues markedly influenced the SCFs’ abilities to stabilise SOC. The removal of sesquioxides from the SCFs significantly decreased their C stabilisation capacity, which coincided with a decrease in the dehydrogenase activity of the mineral-residue mixture. The allophanic SCF showed the least microbial activity and the greatest C stabilisation due to having a higher proportion of micropores (75%). The high C stabilisation capacity of allophanic SCF could also be explained by its high specific surface area (119 m 2 g −1 ). The results of this study are helpful to understand the role of various SCFs in stabilising added C originating from external wheat residue addition but warrant further validation under field conditions. Refereed/Peer-reviewed

Cauliflower (Brassica oleracea var. botrytis L.) requires large amounts of nitrogen (N) fertilizer to produce high yields. The intercropping of cauliflower with a leguminous species may help farmers to reduce N fertilizer rates, production costs and environmental pollution. Moreover, the recycling of crop residues can contribute to the nutritional support of subsequent crops in a rotation. In this study, cauliflower was cultivated in year one either alone or intercropped with annual clover (Trifolium resupinatum L.), using four N fertilization rates: 0, 75, 150, and 300 kg N ha−1 (referred to as N0, N1, N2, and N3 respectively). Following crop residue incorporation in year two, iceberg lettuce (Lactuca sativa var. capitata (L.) Janchen) was cropped on the same field without the supply of N fertilizer to assess the effect of cauliflower and clover residues as well as of residual N fertilizer rates on the growth and N uptake of lettuce. The presence of clover did not affect the marketable yields of the intercropped cauliflower, which were similar to the cauliflower sole-cropped. The N1 and N2 fertilizer rates maximized both growth and N uptake of the intercropped cauliflower, while with the N3, crop development was limited. In the N0 plot, the legume competed for N and depressed growth and N absorption of cauliflower. The sole-cropped cauliflower was, on the contrary, unaffected by the N fertilizer rates. The iceberg lettuce cultivated in succession benefited from the presence of clover in plots N1 and N2. When succeeded to the sole-cropped cauliflower, however, the iceberg lettuce produced less biomass and absorbed less N. Results from this study suggest that the intercropping system cauliflower-clover can be a sustainable tool to optimize N input and reduce N fertilizer requirements for the successive crop.

Cauliflower (Brassica oleracea var. botrytis L.) requires large amounts of nitrogen (N) fertilizer to produce high yields. The intercropping of cauliflower with a leguminous species may help farmers to reduce N fertilizer rates, production costs and environmental pollution. Moreover, the recycling of crop residues can contribute to the nutritional support of subsequent crops in a rotation. In this study, cauliflower was cultivated in year one either alone or intercropped with annual clover (Trifolium resupinatum L.), using four N fertilization rates: 0, 75, 150, and 300 kg N ha−1 (referred to as N0, N1, N2, and N3 respectively). Following crop residue incorporation in year two, iceberg lettuce (Lactuca sativa var. capitata (L.) Janchen) was cropped on the same field without the supply of N fertilizer to assess the effect of cauliflower and clover residues as well as of residual N fertilizer rates on the growth and N uptake of lettuce. The presence of clover did not affect the marketable yields of the intercropped cauliflower, which were similar to the cauliflower sole-cropped. The N1 and N2 fertilizer rates maximized both growth and N uptake of the intercropped cauliflower, while with the N3, crop development was limited. In the N0 plot, the legume competed for N and depressed growth and N absorption of cauliflower. The sole-cropped cauliflower was, on the contrary, unaffected by the N fertilizer rates. The iceberg lettuce cultivated in succession benefited from the presence of clover in plots N1 and N2. When succeeded to the sole-cropped cauliflower, however, the iceberg lettuce produced less biomass and absorbed less N. Results from this study suggest that the intercropping system cauliflower-clover can be a sustainable tool to optimize N input and reduce N fertilizer requirements for the successive crop.

Within the domain of phytoremediation research, the proper disposal of harvestable plant parts, that remove pollutants from contaminated soil, has been attracted extensive attention. Here, the bioenergy generation capability of trace metals (Cu, Pb, Zn, Cd, Mn, and As) polluted plants was assessed. The biogas production potential of accumulators or hyperaccumulator plants, Elsholtzia haichowensis, Sedum alfredii, Solanum nigrum, Phytolacca americana and Pteris vittata were 259.2 ± 1.9, 238.7 ± 4.2, 135.9 ± 0.9, 129.5 ± 2.9 and 106.8 ± 2.1 mL/g, respectively. The presence of Cu (at approximately 1000 mg/kg) increased the cumulative biogas production, the daily methane production and the methane yield of E. haichowensis. For S. alfredii, the presence of Zn (≥ 500 mg/kg) showed a significant negative impact on the methane content in biogas, and the daily methane production, which decreased the biogas and methane yield. The biogas production potential increased when the content of Mn was at 5 000–10,000 mg/kg, subsequently, decreased when the value of Mn at 20,000 mg/kg. However, Cd (1–200 mg/kg), Pb (125–2000 mg/kg) and As (1250–10,000 mg/kg) showed no distinctive change in the cumulative biogas production of S. nigrum, S. alfredii and P. vittata, respectively. The methane yield showed a strong positive correlation (R2 = 0.9704) with cumulative biogas production, and the energy potential of the plant residues were at 415–985 kW h/ton. Thus, the anaerobic digestion has bright potential for the disposal of trace metal contaminated plants, and has promising prospects for the use in energy production.

Soil organic C (SOC) accumulation is known to increase by practices of increasing plant residue C inputs, while the SOC stabilization efficiency relative to C inputs is variable. The SOC stabilization efficiency in a Kastanozem soil (up to 21% of C inputs) is much greater than the global average (0.7%). To test whether litter is preserved by transformation into the mineral-associated SOC pool in a Kastanozem soil, we conducted a four-year incubation study of 13C-labeled maize residue in Saskatchewan, Canada. We monitored whether litter residue inputs are transformed and stabilized into the mineral-associated heavy fraction (>1.60 g cm−3). The litter decomposition rates in our study were the lowest among the global dataset due to the limited microbial activities under cold and arid climate. Fractionation of SOC into light and heavy fractions ( 1.60 g cm−3, respectively) and subsequent analysis using nuclear magnetic resonance spectroscopy indicated that both the light and heavy fraction pools of transformed maize litter were enriched by microbial lipids, along with aromatic and carboxylic groups. The heavy fraction exhibited the lower decomposition rates than the light fraction due to selective loss of cellulose. This leads to the greater SOC stabilization in the heavy fraction (14% of the litter input) after the 4-year incubation period, compared to the light fraction (7%). Global temperature-dependency of microbial activities can account for slow litter decomposition under semi-arid and cold prairie, while the high stabilization efficiency of the litter-derived C is supported by microbial transformation and the relatively high capacity of mineral association in Kastanozem soils.

Filtrate made from the burnt ash of crop plant residue is used in cooking in Northern Uganda. This practice is believed to decrease the cooking time of hard-to-cook legumes and provide a culturally preferred taste. The objectives of this study were to: (1) compare cooking times and sensory preferences for dried black beans (Phaseolus vulgaris L.) among four treatments: plain water (control), table salt, crude ground salt, and ash filtrate; and (2) determine demographic factors (gender, age, and education) that may also influence preferences. Sensory preferences for beans cooked across the treatments were evaluated through blind taste tests. Analysis of variance (ANOVA) with post-hoc Bonferroni multiple comparisons showed a statistically significant (p < 0.01) 27% reduction in cooking time with the addition of ground salt and 18% shorter cook time with ash filtrate. Contrary to anecdotal belief, participants showed an overall preference for black beans cooked with ground salt and table salt over plain beans or those cooked with ash filtrate. The type of treatment and study site significantly (p