Effects of salinity on growth and on valve morphology of five estuarine diatoms

The effects of salinity on the growth and valve morphology of five benthic estuarine diatoms (Nitzschia pusilla, N. frustulum, N. palea, N. filiformis var. conferta and Eolimna subminuscula), isolated from both freshwater and brackish/marine habitats, were investigated. The four Nitzschia strains grew well over a broad salinity range, though some (N. pusilla, N. frustulum) showed a broader salinity range tolerance (from fully saline down to at least 9.5 ppt) than others (N. palea, N. filiformis var. conferta had reduced growth at salinities of 16 ppt and above). Salinity significantly affected the valve morphology of the five strains studied. However, there was no consistent pattern in either the morphological characters affected or the direction of the effects. Although significant, the effects of salinity on valve morphology were very small and therefore it seems that the taxonomic usefulness of some of the classical taxonomical characters is not undermined.     

Processing samples of benthic marine diatoms from Mediterranean oligotrophic areas

The processing of benthic diatoms is tedious and involves several potentially damaging steps for cells. Although the preservation of siliceous frustules is of paramount importance in the implementation of biotic indices, only few studies quantified treatment-induced cell losses. We assumed that commonly used treatments may lead to mechanical (centrifugation, sedimentation, boiling, sonication and mounting in Naphrax) and chemical (cold H₂O₂ digestion) damages on diatoms. We analysed the potential adverse effects of these treatments and the cleaning efficiency of H₂O₂ and incineration in order to find out the most suitable technique to process lightly silicified Mediterranean populations. Results showed that successive resuspensions of material after each concentration treatment (sedimentation and centrifugation) and low speed centrifugation did not alter the physical integrity of frustules. In contrast, boiling and sonication exhibited adverse effects especially on the preservation of large frustules and Naphrax mounting proved to be the most damaging step whatever the size of diatoms. For cleaning treatments, incineration provided the most satisfactory results and acted on a non-selective way as opposed to hydrogen peroxide which led to either a large number of non-cleaned frustules or dissolved valves. Our recommendations for processing samples of lightly silicified Mediterranean benthic diatoms include the use of low-speed centrifugations, dehydration at room temperature, incineration and dry mounting.     

氮磷营养因子对赤潮异弯藻生长的影响

研究了N、P营养浓度对赤潮异弯藻(Heterosigma akashiwo)生长的影响.结果表明,该藻的生长速率与N、P营养因子浓度的关系符合Monod公式.在NO₃^--N浓度达到7.5 mg·L^-1时,赤潮异弯藻开始生长;浓度为3.75～75 mg·L^-1时,赤潮异弯藻的比生长速率与NO₃^--N浓度成正比关系.N营养充足时,赤潮异弯藻的最大生长速率μ_m-n=0.3475·d^-1,K_s-n=18.91 mg·L^-1.PO₄^--P浓度为0～1.0 mg·L^-1时,赤潮异弯藻的比生长速率与P浓度成正比关系;P营养充足时,赤潮异弯藻的最大生长速率μ_m-p=0.3024·d^-1,K_s-p=0.4086 mg·L^-1.N/P达到25后藻细胞浓度达到最大,表明N/P为25时最适合赤潮异弯藻生长.赤潮异弯藻最适合在N 37.5～225.0 mg·L^-1、P 5.0～50.0 mg·L^-1、N/P=25条件下生长.     

Optimal colonization and growth of marine benthic diatoms on artificial substrata: protocol for a routine use in bioindication

Benthic diatoms growing on hard substrata are used for their bioindication ability in freshwater quality monitoring. Artificial substrata are needed in cases where any natural substrate is present or to achieve similar sampling conditions between sites. Prior to use marine benthic diatoms for monitoring, a standardized protocol for sampling on artificial substrata must be set up. Two major types of information are required: (1) the time needed for a diatom community to be well developed and mature (climax stage); (2) the optimal growth conditions, given that the substrataum nature and texture are important parameters for the initial phase of biofilm development and can influence the future diatom assemblage. Three substrataum types were tested: frosted Plexiglass®, frosted glass, and rough enameled tiles. They were submerged for 8 weeks and sampled weekly. The experiment was conducted at five sites of distinct morphology and water chemistry, along the coastal area of Martinique Island, French West Indies. Development of diatom community was studied through biofilm dry weight, valve density, species richness, and species relative abundances. Globally, substratum type had no significant effect on any parameter. Frosted Plexiglass® was found to be the most interesting substratum because of higher valve densities and practical use. The asymptotic phase of biofilm development was encountered between 5 and 8 weeks depending on site and parameter. A compromise between community development and vandalism or loss through time was fixed to 5 weeks. This period is longer than for stream environments and is valid for tropical oligotrophic marine environments.     

Effects of density on growth rates of four benthic diatoms and variations in biochemical composition associated with growth phase

Diatom cell quantity and their biochemical composition vary among species and are greatly affected by harvest stage or culture conditions. This study compares growth pattern, cell attachment, and biochemical composition of four diatoms suitable for abalone post-larvae: Navicula incerta, Proschkinia sp., Nitzschia sp., and Amphora sp. The four diatoms were grown in F/2 medium at 28.5?±?1.4°C, under 62?±?8?μmol?photons?m^?2?s^?1, at different original inoculating densities (0.05?×?10⁶, 0.10?×?10⁶, and 0.25?×?10⁶?cells?mL^?1) and were harvested in log and stationary phase of growth for biochemical analysis. Total protein, carbohydrate, lipid, and ash composition, as well as fatty acid composition, were determined. All diatoms grew better when inoculated at 0.10?×?10⁶?cell?mL^?1 with Proschkinia sp. reaching the highest cell density of 6.56?×?10⁶?cells?mL^?1 in log phase. Amphora sp. had the highest cell attachment capacity when inoculated at 0.10?×?10⁶?cell?mL^?1 (11,580?cells?mm^?2), whereas N. incerta had the lowest (7,750?cells?mm^?2). Protein and lipid (percent dry weight) contents were generally highest in cells during log phase of growth; Amphora sp. in log phase of growth had the highest lipid content of 9.74% DW, whereas significant differences in carbohydrate between the two growth phases were only observed for Proschkinia sp. Besides, all diatoms had higher energy contents in log phase of growth. There were no significant differences in ash content among the four diatoms. Polyunsaturated fatty acid (PUFA) content ranged from 23.25% to 38.62% of the total fatty acids, and the four diatoms tested were richer in n-3 PUFA than in n-6 PUFA. All the diatoms had significant quantities of 20:5n-3 (EPA) (between 12.69% and 17.68% of TFA), and Proschkinia sp., in log phase of growth, had the highest quantity of arachidonic acid (20:4n-6; ARA). The results highlight the influence of culture conditions and harvest protocols on diatom nutritive value and enabled a preliminary approach towards the selection of novel diatom species.     

The combined effect of nitrogen,phosphorus and iron on the growth of Selenastrum gracile reinsch

Mathematical regression models are given which describe the dependence of the growth of the alga Selenastrum gracile Reinsch on the available concentrations of nitrogen, phosphorus and iron. From these models the optimum concentrations of these elements were obtained. The culture growth in its phases is affected by phosphorus and iron and by their interaction effect, while in later phases growth is accelerated by nitrogen and phosphorus and by their interaction effect.     

Effects of different nitrogen species on sensitivity and photosynthetic stress of three common freshwater diatoms

Different sources of nitrogen pose diverse effects to algal community, but the mechanism of inhibitory effects of nitrogen sources on freshwater diatoms is not fully understood. The purpose of this study was to compare biomass, photosynthetic activity, and morphological structure of three common freshwater diatoms (Cyclotella meneghiniana, Nitzschia sp., and Gomphonema parvulum) under different nitrogen sources (NO₃ ^? or NH₄ ⁺). The sorption characteristic of each diatom was investigated, and chlorophyll a (Chl-a) content and oxygen evolution rate were analyzed to investigate stress of different nitrogen sources on each diatom in the batch experiments. Ammonium lowered the growth rate of C. meneghiniana and Nitzschia sp. when it was supplied in addition to growth-saturating nitrate concentrations, suggesting a combined effect of inhibition of nitrate uptake and direct ammonium stress. Oxygen evolution rate of Nitzschia sp. showed that the direct ammonium stress on the photosynthetic activity can be alleviated by coexistence of nitrate in the nitrogen enriched treatment, but not for C. meneghiniana and G. parvulum, which may be caused by a different nitrate transporter system within algal cells. Transmission electron microscopy was used to assess the toxicity of ammonium on ultrastructural chloroplast of each diatom. Ultrastructural changes in chloroplasts showed undefined electron-dense granules and lipid droplets, but the membrane integrity of cell was maintained, suggesting an adaptation to adjustment to ammonia stress. Results showed that Cyclotella meneghiniana and Nitzschia sp. were more sensitive to ammonium stress than Gomphonema parvulum on growth, but the mechanism remains unclear.     

氮、磷、铁对三角褐指藻诱变株生长、总脂及脂肪酸的影响

为了优化微藻培养条件,采用单因子试验研究了不同氮浓度(5、10、15、20、25、30和35 mg·L~(-1))、不同磷浓度(0.5、1.0、1.5、2.0、2.5、3.0和3.5 mg·L~(-1))、不同铁源(Fe Cl3、Fe C6H5O7和Fe SO4)和铁浓度(0、0.10、0.25、0.50和1.00 mg·L~(-1))对三角褐指藻紫外诱变株MP-2的影响。结果表明:氮、磷、铁对MP-2的生长、总脂含量和脂肪酸组成影响显著(P0.05);MP-2生长最适氮浓度为20 mg·L~(-1),其生长速率K值和生物量分别为(0.384±0.004)和(0.25±0.01)g·L~(-1),氮浓度为30 mg·L~(-1)时总脂积累量最高(26.51±1.96)%,氮浓度25 mg·L~(-1)时PUFA积累最高[(37.78±0.35)%];MP-2生长最适磷浓度为2.5 mg·L~(-1),生长速率K值和生物量分别为(0.305±0.010)和(0.28±0.02)g·L~(-1),磷浓度1.0 mg·L~(-1)时总脂积累量最高[(21.79±0.89)%],磷浓度为2.5 mg·L~(-1)时PUFA积累最高[(39.33±0.38)%];Fe SO4为铁源时生长最佳,显著优于其余各组(P0.05),生长最适铁浓度为0.50 mg·L~(-1),生长速率K值和生物量分别为(0.495±0.006)和(0.87±0.04)g·L~(-1),铁浓度0.25 mg·L~(-1)时总脂积累量最高[(28.86±0.50)%],铁浓度1.0mg·L~(-1)时PUFA积累最高[(41.73±0.42)%]。由此可见,MP-2生长、总脂和PUFA积累所需的氮、磷、铁需求量不同,在生产性培养时最好采用二次培养。     

Effects of macroalgal species identity and richness on primary production in benthic marine communities

Plant biodiversity can enhance primary production in terrestrial ecosystems, but biodiversity effects are largely unstudied in the ocean. We conducted a series of field and mesocosm experiments to measure the relative effects of macroalgal identity and richness on primary productivity (net photosynthetic rate) and biomass accumulation in hard substratum subtidal communities in North Carolina, USA. Algal identity consistently and strongly affected production; species richness effects, although often significent, were subtle. Partitioning of the net biodiversity effect indicated that complementarity effects were always positive and species were usually more productive in mixtures than in monoculture. Surprisingly, slow growing species performed relatively better in the most diverse treatments than the most productive species, thus selection effects were consistently negative. Our results suggest that several basic mechanisms underlying terrestrial plant biodiversity effects also operate in algal-based marine ecosystems, and thus may be general.     

Nutrient-induced competition between two species of marine diatoms

Competition experiments betweenPhaeodactylum tricornutum andSkeletonema costatum showed that even at temperatures higher than 10°C (i.c. 14°C), the development ofSkeletonema can be favoured by adjusting nutrient levels and nutrient ratios. Low NSi ratios were found to favourSkeletonema. Additionally, high NP ratios further enhanced the ability ofSkeletonema to dominate the cuftures. Contrary to some statements in literature, it seems that high concentrations of silicates are more important for the dominance ofSkeletonema costatum in large-scale cultures than just low temperatures. This finding is important with regard to stimulating the blooming ofSkeletonema costatum in natural phytoplankton populations as food for bivalve molluscs.     

氮磷硅添加对青藏高原高寒草甸垂穗披碱草叶片碳氮磷的影响

以甘南高寒草甸常见牧草垂穗披碱草(Elymus nutans)为研究对象,比较不同氮磷硅添加下,垂穗披碱草叶片对元素添加的反应。研究发现:氮添加显著提高土壤中硝态氮和铵态氮的含量;磷添加提高了土壤中全磷和速效磷的含量;高浓度的硅单独、硅与氮或磷混合可提高土壤中硝态氮的含量或全磷和速效磷的含量;氮和磷单独添加分别能提高垂穗披碱草叶片全氮和全磷含量,高浓度的硅单独、硅与氮或磷混合添加都能提高垂穗披碱草叶片全氮和全磷的含量。就硅元素而言,高浓度的硅添加,硅与氮或磷混合添加能提高土壤硝态氮、全磷和速效磷的含量,促进垂穗披碱草对土壤中氮磷的吸收,从而使植物叶片中氮磷的含量增加。     

Effects of nitrogen and phosphorus on blue grama growth and mycorrhizal infection

Summary The purpose of this study was to examine the growth response of Bouteloua gracilis, with and without the vescular-arbuscular mycorrhiza (VAM), Glomus fasciculatus, to varying levels of phosphorus and nitrogen (as NH ₊ ⁴ ) and to determine whether nitrogen and phosphorus levels influence VAM establishment. Bouteloua gracilis was grown in 225 g of soil in a factorial experiment combining four levels of ammonium nitrogen (4, 30, 60, and 126 g/g), four levels of phosphorus (3, 7, 12, and 22 g/g), and with VAM spores or no spores. Bouteloua gracilis showed enhanced growth with increased nutrients over the entire range of experimental amendments. Shoot nitrogen concentration for all plants ranged from an average of 0.73% at the low amendment level to 1.61% at the high level, whereas shoot total averages ranged from 2.43 mg at the low amendment to 16.4 mg at the high amendment. Mean shoot phosphorus concentrations ranged from 0.109% at the low amendment level to 0.150% at the high amendment, while totals averaged 5.29 mg at the low amendment and 11.8 mg at the high amendment level. Infected plants were consistently smaller than uninfected plants. This reduction was significant at high nitrogen-low phosphorus, where percent infection was highest (71%). At low nitrogen levels, moderate infection (17%) was established at all phosphorus levels. No infection occurred when both nitrogen and phosphorus levels were high. The lack of a positive nutrient or biomass response to VAM establishment is contrary to most published reports, but is similar to a lack of response shown with certain grasses and other plants. It is possible that the parasitic nature of the response to infection represents the early phase of infection.     

Effects of light intensity variation on nitrogen and phosphorus contents,allocation and limitation in five shade-enduring plants

Aims To enhance the understanding on nitrogen (N) and phosphorus (P) physiological responses to different light environments in shade-enduring plants and provide references to improve the stand structure and ecosystem functions of plantation forests.Methods We selected seedlings of five shade-enduring species with high ecological and economic value in subtropical area of China to study the effects of light intensity on leaf N and P contents, allocation and nutrient limitation in shade-enduring plants. A light intensity gradient of five different levels was set to simulate the varying understory light environment.Important findings With decreasing light intensity, the total biomass and total N and P accumulation of five shade-enduring plants all showed a decreasing trend, but N, P contents in different organs increased. Among them, Gardenia jasminoides (GJ) had the highest while Illicium henryi (IH) had the lowest N content; The P contents of Quercus phillyraeoides (QP) and GJ were significantly higher than Elaeocarpus sylvestris (ES), Ardisia crenata (AC) and IH. QP and GJ had the highest N, P contents under extremely low light intensity (6% natural light intensity) condition (LIC), while AC and IH had the highest N and P contents in low (15% natural light intensity) and moderate (33% and 52% natural light intensity) LIC. ES demanded differently for LIC on N and P, which were 52% and 6% natural light intensity, respectively. N and P allocation of ES, AC and IH followed leaf > root > stem, but for QP and GJ were root > leaf > stem. Decreasing LIC significantly affected N and P allocation. N content variations shown good consistency among different organs under higher LIC (100% natural light intensity) while distinct variability under lower LIC (15% and 6% natural light intensity) in all five species. Phosphorus contents exhibited good consistency in IH, QP and GJ but varied in ES and AC. Decreasing LIC significantly affected organ N/P ratios of shade-enduring plants, but the fundamental growth restriction patterns remained. Light intensity variation and tree species co-regulated N, P utilization and allocation in shade-enduring plants, and then affected the total biomass and total N, P accumulation, which might result from the change of N and P utilization strategy. Therefore, light intensity preference and N, P nutrient balances in shade-enduring plants should be taken into account when constructing multiple layer and uneven-aged forests.     

N、P营养盐对海洋卡盾藻（Chattonella marina）生长的影响

在实验室条件下,设置不同的N、P浓度,研究N、P双因子限制(N:5-500ug·L-1,P:0.74-74ug·L-1,N:P=15)及单因子限制(N:500ug·L-1,P:0.74-741ug·L-1和P:74ug·L-1,N:5-500ug·L-1)对海洋卡盾藻生长的影响.结果表明:在高N、P浓度(N:500ug·L-1,P:74ug·L-1)条件下海洋卡盾藻具有相对较高的比生长率(O.788/d),稳定期持续时间较长,最大细胞密度可达8850 cells/ml.N、P限制能明显抑制海洋卡盾藻的生长,而N限制对海洋卡盾藻生长影响更大,N限制组的比生长率和稳定期细胞密度均明显低于P限制组和N、P双因子限制组.结果说明海洋卡盾藻生长对N变化更为敏感,但随着海洋污染的加剧,海水中N含量持续上升,卡盾藻可迅速爆发性增长并引发赤潮,这也许是近年来我国沿海卡盾藻赤潮频繁发生的重要原因之一.     

Effects of phosphorus and nitrogen amendments on the growth of Egeria najas

The effect of nutrient addition on the growth of E. najas was evaluated in a dose response experiment using sand amended with phosphorus (P) and nitrogen (N), and in enrichment trials with N and P amendments to natural sediments. Plants, water and sediment came from lagoons of the Upper Paraná River Floodplain and from Itaipu Reservoir (Brazil). Relative growth rates (RGRs) of E. najas shoots, based on dry mass (DM), varied from 0.03 to 0.060 d⁻¹ for both nutrients. Root:shoot biomass ratios were related to sediment exchangeable P (r = −0.419; P = 0.03) and N (r = −0.54; P = 0.006), however root RGR was not related to sediment nutrient concentrations. When natural sediments were amended with N and P, neither shoot nor root RGRs differed among treatments for substrata from either the reservoir or the floodplain lagoons (P > 0.05). Comparison of nutrient concentrations measured in natural sediments collected from several sites in both the Upper Paraná River Floodplain (range 49–213 μg P g⁻¹ DM; 36–373 μg N g⁻¹ DM) and Itaipu Reservoir (range 43–402 μg P g⁻¹ DM; 7.9–238 μg N g⁻¹ DM) showed that sediment N and P from these systems usually exceeded minimum requirements necessary for E. najas growth, as measured in the dose response experiment. Together, these results indicate that E. najas, at least in early stages of development, responds to sediment nutrient amendments and relies upon bottom sediments to meet its N and P requirements and that for at least two Brazilian ecosystems, growth of this species is not limited by insufficient sediment N or P. Thus, reducing N and P in water is not enough to control E. najas growth in short time periods in these ecosystems.     

氮磷施肥对拟南芥叶片碳氮磷化学计量特征的影响

研究植物碳(C)氮(N)磷(P)化学计量特征, 有助于了解C、N、P元素的分配规律和确定限制植物生长的元素类型, 理解生长速率调控的内在机制。该研究基于盆栽施肥试验, 测定不同N、P供应水平下拟南芥(Arabidopsis thaliana)叶片的生物量和C、N、P含量, 分析拟南芥的限制元素类型、验证生长速率假说、探讨N、P的内稳性差异和C、N、P元素间的异速生长关系。主要结果如下: 盆栽试验基质中限制元素是P, 施N过多可能引起毒害作用; 拟南芥的生长符合生长速率假说, 即随着叶片N:P和C:P的增加, 比生长速率显著减小; 叶片P含量存在显著的调整系数(3.5), 但叶片N含量与基质N含量之间无显著相关; 叶片N和P含量具有显著的异速生长关系, 但不符合N-P^3/4关系, 施P肥导致表征N、P异速生长关系的幂指数(0.209)显著低于施N肥处理(0.466)。该研究首次基于温室培养实验分析了拟南芥C、N、P的化学计量特征及其对N、P添加的响应, 研究结果将为野外研究不同物种、群落或生态系统的化学计量特征提供参考。     

Comparison of iron,manganese, and phosphorus retention in freshwater littoral sediment with growth of Littorella uniflora and benthic microalgae

Sediment columns from an oligotrophic lake were percolatedwith artificial porewater in two 46-day experiments toexamine the effects of Littorella uniflora and benthicmicroalgae on retention of phosphorus (P) by either iron(Fe) or manganese (Mn). Cumulative retention of P, Fe, andMn was 2–5 times higher in sediment with L. uniflora thanin sediment with microalgae, because of higher P uptake andmore efficient Fe and Mn oxidation by L. uniflora than bymicroalgae. Thus 34% and 21%of added P was retained in L. uniflora inhabited sediments asmetal-oxide bound P compared to 11% and2% in microalgae inhabited sediments, inexperiments supplied with Fe and Mn, respectively. Theatomic ratio of Fe/P precipitation was about 1 and forMn/P precipitation it was about 5. These ratios indicateprecipitation of Fe(III)-phosphate (strengite) and metastableMn(IV)-compounds containing phosphate and hydroxide ions invariable amounts. In addition to metal-oxide P precipitation,increased P retention in the vegetated sediment was also causedby the presence of humic acid compounds, which accountedfor about 26% of total retained P.     

模拟降水变化和土壤施氮对浙江古田山5个树种幼苗生长和生物量的影响

为了探讨古田山地区5个树种—秃瓣杜英(Elaeocarpus glabripetalus)、枫香(Liquidambar formosana)、木荷(Schima superba)、青冈(Cyclobalanopsis glauca)和马尾松(Pinus massoniana)幼苗的生长和生物量及其分配对添加氮肥和减少降水的响应, 在野外设置了双因素氮肥(对照和施氮)和降水(自然降水(对照)和减少降水)控制试验, 氮肥的施入量为10 g·m^-2·a^-1 NH₄NO₃, 分别于每年5月初和7月初各施5 g·m^-2·a^-1, 减少降水处理是减少自然降水的30%。经过3个生长季的处理发现: 1)施氮显著促进了秃瓣杜英、枫香和木荷的苗高和基径的生长, 并且对秃瓣杜英和枫香的促进作用经过1个生长季的处理就表现出来, 而木荷在经过2个生长季后才表现出来; 2)施氮显著促进了秃瓣杜英、枫香和木荷的全株生物量以及各部分生物量的增长, 而只增加了马尾松的侧枝和叶片生物量以及青冈的侧枝生物量; 3) 2个生长季的施氮处理提高了秃瓣杜英和木荷的叶重比以及枫香和青冈的枝重比, 3个生长季的施氮处理促进了秃瓣杜英、枫香和木荷的茎重比以及青冈和马尾松的枝重比, 地上干物质分配比例的增加以地下干物质分配比例减小为代价, 施氮后显著降低了秃瓣杜英、枫香、木荷和青冈的根重比和根冠比; 4) 降水减少30%对各树种的生长均无显著影响。     

Effects of intercropping sugarcane and soybean on growth, rhizosphere soil microbes, nitrogen and phosphorus availability

The effects of sugarcane plantation intercropped with soybean on plant growth, yield, enzyme activity, nitrogen and phosphorus contents, the microbe quantity of rhizosphere soil were investigated. Results showed that dry weight of biomass and yield under sugarcane/soybean intercropping were increased by 35.44 and 30.57 % for sugarcane, and decreased by 16.12 and 9.53 % (100-grain weight) for soybean, respectively. The nitrogenase activity of intercropping soybean nodule was significantly increased by 57.4 % as compared with that in monoculture models. The urease activities of intercrops sugarcane and soybean were promoted by 89 and 81 % as compared to that of the monoculture models, respectively. The effective nitrogen and phosphorus contents of rhizospheric soil of intercrops sugarcane and soybean were increased by 66 and 311.7 %, respectively, as compared to those in the monoculture system. Microbe number of rhizosphere soil in the intercropping pattern increased significantly as compared to those in the monoculture models. The quantities of bacteria, fungi, and actinomyces increased by 42.62, 14.5 and 78.5 % in the intercropping sugarcane, while the intercropping soybean increased by 188, 183 and 73 %, respectively. Therefore, growing sugarcanes in combination with soybean can be considered a good agriculture management practice, helping to promote plant growth, yield and increase soil nutrients.