Naturehydro Horticulture Grow
Studies identified mutton as a core food staple, comprising 6% of the total energy and 10% of the total protein consumed in the Diné diet. The current study participants reported that 35% of their total protein meat intake is comprised by local O. aries.In the study community, the typical serving size per foodstuff is reported …
Continue reading “The mean intake of local sheep protein was reported to be one day per week”
While the GUC is an economic and cultural engine, it is surrounded by seven low income and racially segregated neighborhoods. The median income for households in these communities is $18,500; it is $47,626 in the rest of the city . Unemployment sits at 24 percent, nearly three times the rate for the city at large . …
The GM varieties that have been developed and adopted extensively to date have not experienced significant price discounts because of buyer resistance. This can probably be attributed to the nature of the crops. For feed grains, the buyers are other farmers who are comfortable with the technology, and for fiber crops such as cotton the …
However, more work is required to determine how to better represent coupled microbe–plant nutrient competition and transport limitations. For example, we have previously shown that one can apply a homogenous soil environment assumption and include the substrate diffusivity constraint in the ECA competition parameters. In this approach, the diffusivity constraint can be directly integrated into the substrate …
Continue reading “Nutrients would diffuse and advect from the bulk soil toward the root zone”
As a consequence, a larger amount of product can be delivered earlier, which can help to prevent the disease from spreading once a vaccine becomes available. In addition to conventional chromatography, several generic purification strategies have been developed to rapidly isolate products from crude plant extracts in a cost-effective manner . Due to their generic nature, …
The dry biomass measurement showed highly unexpected results, with the TP-Effluent having more biomass accumulation than even TAP. One explanation for this result is that the residual chemicals in the effluent were not properly washed away or evaporated during the dry biomass collection process. KHCO3 is a salt that could have been retained in the dry …
The viral decay rate in the soil determined by Roberts et al. was adopted because the experimental temperature and soil type are more relevant to lettuce growing conditions compared to the other decay study . Decay rates in the root and shoot were used from the hydroponic system predictions.The transport model was fitted to log10 viral concentration data from …
When looking at the effects of CO2 the different seedling treatments were combined. When looking at the effect of CO2 on any growth or weathering parameters, only planted columns were considered. Statistical analysis was performed using JMP software version 5.01a . Two way ANOVA was used to determine treatment and interaction effects. Significant differences between CO2 treatments were assessed with a student T test, and significant differences between ectomycorrhizal treatments with Tukey’s HSD test, using a one way ANOVA.Upon harvest we observed highly variable rates of mycorrhizal colonization. We classified the seedlings as abundantly colonized , moderately colonized , or sparsely colonized . Of the 20 seedlings in the mycorrhizal treatments 6, 4, and 10 seedlings were abundantly, moderately, and sparsely colonized, respectively, at the time of harvest. While the root systems extended 12S21 cm down the 30 cm columns, no mycorrhizae were found deeper than 6 cm. There were no extraradical hyphae or ectomycorrhizae resembling Piloderma& fallax or Suillus&variegatus observed in the non mycorrhizal treatment, but there were turgid, smooth,maceta cuadrada plastico black root tips observed in the non mycorrhizal treatments that may have been Thelephoroid mycorrhizae. Chitin analysis of roots and growing medium showed almost no chitin in our unplanted controls, and significant chitin in both mycorrhizal treatments . There were also significant amounts of chitin in the non mycorrhizal planted treatments. In both mycorrhizal treatments most chitin was found in the mineral mix, whereas in the non mycorrhizal treament most chitin was found in the rhizosphere and roots. Combining the two mycorrhizal treatments we found moderately more chitin in the elevated CO2 treatment, 86 mg chitin/column vs. 50 mg chitin / column . When the chitin content was expressed as total chitin content per gram seedling biomass , we see that the mycorrhizal treatments did have significantly more chitin than the non mycorrhizal treatment, and that elevated CO2 was associated with a higher chitin content in the Piloderma treatment.Formic, lactic, and acetic acids made up the majority of measured low molecular weight organic acids , comprising 82%, 12%, and 4% of total LMWOA’s, respectively.Much smaller amounts of malonate, oxalate, fumarate, and succinate were occasionally detected, but their occurrence in measurable quantities was not associated with any treatment. Nonplanted columns had significantly lower LMWOA levels than planted columns while P.&fallax columns had significantly higher LMWOA concentrations than non-planted, but significantly lower levels than either the nonmycorrhizal or S.&variegtus columns . These differences were driven by differences in the production of formate and lactate . Columns exposed to elevated CO2 produced significantly more total LMWOA’s , and this difference was driven primarily by significantly greater formic acid production . When amounts of LMWOA are calculated per gram seedling DW there are no significant differences between mycorrhizal or CO2 treatments .Solution pH was measured for the leachate from 7 sampling dates. Leachate pH was consistently alkaline . The nutrient solution used to water the columns was pH 5. There was no significant difference between elevated and ambient CO2 treatments nor between the non mycorrhizal treatments and the mycorrhizal treatments in leachate pH, but the leachate of the non planted controls was significantly lower in pH than the planted treatments on 5 of the 7 sampling dates and moderately but not significantly lower on the other two sampling dates. The pH of the column leachate from the planted columns did not change appreciably over time, while the leachate from the unplanted columns decreased slightly over time .The needle concentrations of Ca, K, Mg, Fe, and P were all at or above deficiency thresholds for P.&sylvestris , though P is near the lower limit of optimal growth. CO2 treatment had no effect on needle nutrient concentrations and mycorrhizal treatment only affected needle [Ca] . Neither CO2 level nor mycorrhizal treatment had a significant effect on total seedling contents of Ca, K, or Mg despite significant differences in seedling biomass between CO2 treatments. The differences in seedling Ca and K contents between treatments correlated tightly with seedling DW, while the opposite trend was found with Mg. Ectomycorrhizal colonization, particularly with Piloderma, increased seedling Mg concentration.Whole column weathering budgets for the 4 elements: Si, Ca, K, and Mg show no effect of CO2 on total weathering losses . The presence of seedlings, mycorrhizal or not, did significantly enhance weathering losses compared to nonSplanted controls.More Si and Mg were weathered in columns planted with P.&fallax inoculated seedlings, but these differences were not significant . The major pool of weathering losses for Mg, K, and Ca in the seedling treatments was uptake into the growing seedlings; losses of magnesium were particularly dominated by seedling uptake . Silica losses were fairly evenly distributed between ΔCEC and column leachate, while seedling uptake was negligible . As stated previously, ΔCEC was negative for calcium and slightly negative for some K and Mg treatments. When the nutrients added during watering were subtracted from the final budgets the net weathering losses of Ca, K, and Mg in the non planted treatment are negative or only slightly positive ,maceta 7 litros suggesting a “missing sink” for weathering products.Elevated CO2 increased the biomass of the Pinus&sylvestris seedlings. Other studies on coniferous seedlings have generally found a growth stimulation with elevated CO2 , and this trend includes several studies on mycorrhizal Pinus&sylvestris seedlings , although some other studies have failed to find an effect of elevated CO2 on growth . We found a slight reduction in root:shoot with elevated CO2. Most studies on ectomycorrhizal P.& sylvestris seedlings which have noted a growth stimulation from elevated CO2 also found an increase in root:shoot . A decrease in root:shoot does not necessarily indicate reduced below ground C allocation as carbon could be allocated to EM fungi rather than root biomass. If we use Ekblad and Nasholm’s estimate that 9.5% of fungal biomass is chitin, then our observed 21 mg average difference in chitin between elevated and ambient CO2 treatments would correspond to 220 mg more fungal biomass supported by seedlings in the elevated CO2 treatment. This difference would bring the root: shoot ratios of the two CO2 treatments to near parity. Additionally, a given amount of ectomycorrhizal biomass typically has a significantly higher respiration rate than the same mass of fine roots and thus represents more below ground carbon allocation This same explanation for potentially higher below ground carbon allocation despite lower root:shoot applies to our findings of slightly lower root: shoot in the two mycorrhizal treatments vs. the nonmycorrhizal treatment. Low molecular weight organic acid production was strongly associated with seedling biomass across both CO2 and mycorrhizal treatments. While EMF are often mentioned in the literature to produce significant amounts of LMWOA’s, our findings seem to fall in line with the majority of studies examining the EMF role in LMWOA production which fail to find an increase in LMWOA production when comparing EMF and nonSEMF seedlings . However, many of these studies do find that EMF significantly alter the composition of LMWOA’s produced, particularly increasing oxalic acid concentrations , which we did not. Similar to Fransson and Johansson , we did not find that elevated CO2 increased LMWOA production beyond its effect on seedling biomass. Elevated CO2 was associated with significantly increased chitin content in seedlings colonized by Piloderma&fallax, but not with seedlings colonized by Suillus& variegatus;&this increase was due to elevated chitin levels found in the growth matrix, not on the seedling roots. Increased mycorrhizal growth is commonly found in elevated CO2 treatments . Many studies show that this response is highly fungal speciesS specific . It is interesting to note that Fransson and Johansson , in which they assessed the effects of elevated CO2 on mycorrhizal growth of 5 ectomycorrhizal species, also found this strain of Piloderma&fallax responded far more to elevated CO2 than any other fungal species examined. Our finding of no increase in seedling biomass in the mycorrhizal seedlings is not uncommon. Despite the fact that Pinus&sylvestris is considered obligately mycorrhizal, many studies have also found a growth depression of P.&sylvestris with mycorrhizal colonization when mycorrhizal and non mycorrhizal seedlings are compared . Given the high needle nutrient concentrations in our non mycorrhizal seedlings, and the very dense rooting we observed, it seems likely that high nutrient availability, and a very restricted rooting zone were the primary reasons we observed no growth stimulation by mycorrhizaeThe generally low levels of mycorrhizal colonization we observed were likely a result of nutrient levels being too high , or insufficient drainage . The significant amounts of chitin observed in the non mycorrhizal treatments may indicate either the presence of thelephoroid mycorrhizal contamination or saprotrophic fungi growing in the mineral mix. Our visual observations of shiny, turgid, smooth, black roots, and the fact that the majority of the chitin found in the non mycorrhizal treatments was found in the roots and not in the mineral mix suggests some thelephoroid mycorrhizal contamination. The larger size of the non mycorrhizal seedlings and their lower chitin levels indicates that thelephoroid infection was minor. Nutrient levels were sufficient for healthy balanced growth. Leachate concentrations of nutrient cations were steady suggesting that we increased the nutrient amounts sufficiently to keep up with the increasing nutrient demand of the growing seedlings. The fact that none of the needle nutrient concentrations were below sufficiency threshold further suggests that none of the seedlings had severe nutrient deficiencies that could have compromised carbon allocation physiology.The overall negative weathering observed for some mineral nutrients suggests a missing sink somewhere in our weathering budget. The two most likely possibilities are the formation of secondary precipitates that were not extracted upon harvest or a large pulse of weathering in the initial 3 weeks of equilibration , before seedlings were planted. We used a chemical speciation and equilibria model Visual MINTEQ to determine if secondary precipitates may have formed. Given the makeup of LMWOA’s observed, the pH’s measured and the elemental concentrations in the drainage as input parameters the only compound likely to have precipitated would have been Caoxalate, but only in very small quantities <3 uM. This leaves the initial “equilibration flush” as the likely missing sink in our weathering budget. All the columns were treated equally before planting so this missing sink should not affect the merit or interpretation of our results. Overall, and in every individual elemental flux , seedlings had a significant effect on weathering. For the nutrient cations K, Mg, and Ca, extra weathering products were taken up by the seedlings, while for Si, which was not taken up in appreciable quantities , extra weathering products were found on exchange sites in the mineral matrix. Mycorrhizal colonization did not significantly increase weathering rates or nutrient uptake, but seedlings colonized by Piloderma&fallax did exhibit a trend toward increased weathering. More Si and Mg were mobilized in the P.&fallax treatment despite the fact that P.&fallax colonized seedlings were on average smaller, though these differences were not statistically significant. P.&fallax colonized seedlings also had significantly higher Mg concentrations. Elevated CO2 had no effect on the weathering losses of Ca, K, or Si, but increased Mg losses . While seedlings grown in elevated CO2 did have higher plant and fungal biomass, and higher total seedling elemental contents, these increases in nutrient uptake were balanced by reduced leaching losses and not by enhanced mineral dissolution. Soil biota are capable of stimulating weathering of alumina silicate minerals by four distinct mechanisms. Proton&promotion: positively charged hydronium ions exuded by biota bind with partially charged negative surface sites on minerals, displacing cations from the mineral surface and destabilizing Si or Al on mineral surfaces, facilitating their release into solution. Plant growth is generally seen as a net acidifying phenomenon as a plant’s greater uptake of positively charged nutrient cations than negatively charged nutrient anions leads to a plant’s net exudation of protons. Ligand8promotion: an anion, either inorganic or organic, binds to mineral surface cations, again destabilizing the bond energy at the mineral surface stimulating release of surface cations and framework Si or Al. Removal&of&transport&limitation: the removal of weathering products from the surface boundary layer via nutrient uptake or enhanced solution flow eliminates or reduces the constant readsorption of these mineral weathering products that occurs in concert with dissolution, enhancing net dissolution.
We had a very low sequencing success rate and this appeared to be due to contamination of many samples by saprotrophic other fungal infection. Our sampling was done in mid summer, and this may be a time of high root turnover. The levels of nitrogen fertilization applied in this study termed “high” and “low” would be considered “extremely high” and “very high” in natural settings. The highest rates of nitrogen deposition in the eastern US are generally below 20 kg N/ha/yr , and many forests considered to be exhibiting nitrogen saturation associated decline are below 15 kg N/ha/yr . The high and low levels of fertilization employed here are 20 and 6 fold higher than the atmospheric deposition levels in this part of the northeast. Because there was no evidence of an interactive effect of nitrogen treatment and horizon with regards to community composition, we will first discuss our findings in the context of nitrogen addition experiments and then discuss the implications of our findings on horizon preference. There is some evidence that deciduous forests may respond differently to nitrogen deposition than coniferous forests , so, when possible, we will focus on studies done in deciduous forests. We will also not discuss studies that focus exclusively on ectomycorrhizal sporocarp inventories. Sporocarp inventories formed the majority of early studies on the effects of acid deposition on ectomycorrhizal communities, and could be considered the canary in the coal mine that has spurred 2 decades of research following the seminal work by Arnolds . However, there is ample evidence that sporocarp abundance may not be reflective of mycorrhizal abundance . We will address the results of our colonization intensity measurements in the context of rooting distribution,vertical grow system ecosystem biogeochemistry and ecosystem responses to nitrogen deposition.Our findings of a significant shift in ectomycorrhizal species composition are generally in agreement with other investigations on the effects of N deposition on ectomycorrhizal commmmunities. Avis et al. and Lucas and Casper found that nitrogen fertilization significantly impacted ECM community composition in oak forests of the eastern US, as have numerous studies in coniferous forests . Our results stand apart from those of Avis et al. and Lucas and Casper in that they observed significant effects on N fertilization on ECM community composition at N fertilization levels between 20 and 35 kg/ha/yr and in as little as two years, while we found no significant effects of 18 years of 50 kg/ha/yr of N fertilization on ectomycorrhizal community composition. Avis et al. also failed to find a significant community change after 18 years of fertilization at 54 kg/ha/yr. The majority of N addition studies on coniferous plots have found a significant impact of 30S50 kg N/ha/yr on ECM community composition , though Ishida and Nordin failed to find an effect of 12 years of 50 kg N/ha/yr on ECM community composition in a spruce forest. Wallenda and Kottke identified a general threshold for 20S30 kg N/ha/yr before marked changes in the ECM community composition are likely to be observed, although they caution that forest specific factors may change this threshold a great deal in either direction, and at the time of their review, there were no studies on the effects of N addition on ECM communities in deciduous forests. Our findings of a marked reduction in ECM diversity with high N fertilization are also in line with the findings of Avis et al , and Lucas and Casper , which found significantly reduced ECM diversity in their high N treatments, though again, they noted significant decreases in ECM diversity at levels comparable to our “low” N treatment, while we did not. Avis et al. failed to find a significant effect of N addition on ECM diversity. Looking at studies in coniferous forests, a reduction in ECM diversity with N addition seems to be the general finding , but studies have also found no reduction in ECM diversity in forests fertilized with moderate or very high levels of N addition . We could clearly identify certain species to be nitrophilic or nitrophobic but we could not make such characterizations for any higher level phylogenetic groups other than the Clavulinaceae. We found that the Clavulinaceae were generally nitrophobic and this is in agreement with the findings of Avis et al. . Among our 5 most abundant Lactarius species, one was nitrophilic, two were more common in the low nitrogen treatment, and nitrogen had no effect on the abundance of the other two. Lactarius&quietus was also quite abundant in Avis et al.’s study on oak, but they found no consistent reaction to nitrogen fertilization. In their study across a depositional gradient in an Alaskan spruce forest Lilleskov et al. found Lactarius&theiogalus to be dramatically nitrophilic, shifting from 7% to 69% of all root tips from the low to high end of their nitrogen gradient; we found L.&theiogalus to be mildy nitrophilic, occurring in greatest abundance in the low N treatment. Cox et al.’s study across european Picea&abies forests identified the genera Lactarius and Thelepohra/Tomentella to be nitrophilic.Our most abundant species was Cenococcum&geophilum, and it was termed nitrophobic due to its sharply reduced abundance in the high N treatment. Avis et al. found Cenococcum abundance across N treatments variable, with one TRFLP type being nitrophilic and another nitrophobic. Lucas and Casper found Cenoccocum&geophilum abundance increased on oak roots in response to nitrogen fertilization . Avolio et al. looked at ECM community composition on pine and oak seedlings in response to nitrate fertilization and found that Cenococcum abundance increased markedly in response to N fertilization on oaks, and decreased markedly in response to N fertilization on pines. Cenococcum geophilum is widely thought to be acryptic species complex , and we examined the possibility that we had sub-taxa within C.&geophilum that might have a distinct affinity for nitrogen or horizon. Clustering our C.&geophilum sequences at different % similarities did yield different clusters,macetas cuadradas but did not divide this large group according to any horizon or nitrogen affinity. This inability to define Cenococcum’s niche is not uncommon; in a 2007 commentary, Dickie identified Cenococcum as “one notable exception to the rule of niche differentiation”.The ECM communities in the organic and mineral soil were quite distinct, both across all treatments and within a given nitrogen treatment. Our findings of different ECM communities in the mineral and organic horizon is common to other studies which have examined the ECM communities in organic and mineral soil separately , though to date few studies have done so. We found evidence of increased diversity in the mineral soil. Rosling et al. found higher diversity in the mineral soil, while Dickie et al. found lower diversity in the mineral soil, and Scattolin et al. found moderately increased diversity of ECM species in the mineral soil. All three of these studies were done in coniferous forests. Certain species in our study exhibited clear preferences for one horizon or another, and these trends were also applicable to higher phylogenetic classifications. In particular the Russulaceae exhibited a preference for the organic horizon while members of the genus Inocybe, the order Agaricales, and the families Tricholomataceae and Clavulinaceae were significantly more abundant in the mineral soil. In contrast to our findings, Baier et al. and Scattolin et al. found that Lactarius and Russula were generally more abundant in the mineral soil, though they found individual species within both genera that were more abundant in the organic soil; both studies were done in high elevation coniferous forests. Tedersoo et al. found, as we did, that the Agaricales exhibited strong preference for mineral soil, though they also found the Clavulinaceae to be significantly more abundant in the organic horizon, in contrast to our findings. In general, our data suggests greater specialization in the mineral horizon than in the organic horizon. Of the 65 species we found, 31 were found only in the mineral soil, while only eight were found exclusively in the organic horizon. Rosling et al. also found a higher proportion of species occurring exclusively in mineral soil.Across all treatments, the ectomycorrhizal colonization intensity was very similar between the mineral and organic horizon, and this stands in some contrast to the published literature. Very few studies have exhaustively sampled the ectomycorrhizal community in the mineral soil , but those that have, have found as many, if not more, ECM in the mineral soil as in the organic soil . More studies have sampled the upper layers of the mineral soil, and ECM colonization intensity, measured as either percent root length colonized or percentage of fine root tips that are mycorrhizal, is generally lower in the mineral soil .However, Scattolin et al. found that the A and B horizons in a montane spruce forest in Italy had significantly higher mycorrhizal colonization intensity than the organic soil, so our finding of equal or slightly elevated colonization intensity in the mineral soil is not unprecedented. Magill et al. assessed the fine root biomass in the same plots we did two years before we sampled these stands. They found that between 55% and 62% of all fine roots were found in the mineral soil, though they only sampled the top 20cm of mineral soil. Thus, our findings of equivalent or higher colonization intensity in the mineral soil can be interpreted as equivalent or higher mycorrhizal biomass in the mineral soil. Nitrogen addition had no effect on the colonization intensity in the low N treatment or in the organic horizon of the high N treatment, and increased the percentage root length colonized in the mineral soil in the high N treatment. According to Magill et al. , the fine root biomass in the organic horizon in these same stands is 25% and 27% lower in the low and high N treatments, respectively. Fine root biomass in the top 20 cm of the mineral horizon has not been significantly affected by nitrogen treatment, thus the percentage of fine roots found in the mineral horizon increased marginally from 55% to 62% with nitrogen addition . We can thus infer that there is a significantly higher fraction of total ectomycorrhizae in the mineral soil in the high N treatment. There is considerable variation in the literature in reported responses of ECM colonization and fine root biomass to nitrogen addition. The consensus seems to be that nitrogen addition decreases both, but the large number of reports finding the opposite suggests that characteristics of the individual forest being examined may be important to consider. In a meta analysis of 6 studies conducted in 14 forest stands, Treseder et al. found a moderate decrease in %RLC of 5.8% with nitrogen fertilization, but also noted that the responses to N were very heterogeneous. In a meta analysis of boreal forests’ responses to nitrogen addition, Cudlin et al. found a not significant decrease of 10% in percent mycorrhizal colonization. Carfrae at al. and Koren and Nylund found significantly increases in %RLC with nitrogen fertilization. Wöllecke et al. noted a sharp decrease in % RLC with nitrogen fertilization, but this was much more pronounced for the organic horizon than the mineral horizon, also indicating increased fraction of total mycorrhizal activity in the mineral soil under nitrogen addition. To the authors’ knowledge no published studies have examined the effects of nitrogen on ECM colonization intensity in deciduous forests. The literature on the effects of nitrogen on rooting activity is no more consistent. While, many micro and mesocosm studies have demonstrated a decreased ratio of root biomass to shoot biomass with increased N availability , and the mechanisms for this are well understood , the effect is generally driven by increases in above ground biomass and the effects of nitrogen fertilization on below ground biomass in forests vary considerably. Cudlin et al. found an increase in root biomass of 10% in their meta analysis of 22 forest studies, while Ostonen et al. found a 20% decrease in specific root length in a meta analysis of 54 studies, both of these studies reported such high variation in responses to N that neither trend was significant.The altered mycorrhizal colonization we observed in the high N plot may be an adaptation to limitation or colimitation by phosphorous or base cations.
Leaf organic d13C and d18O values support this observation, because P. piscipula showed consistently higher d13C values than G. floribundum , coupled with lower d18O indicating that the decrease in photosynthetic carbon isotope discrimination was associated with greater stomatal conductance and greater photosynthesis . Greater photosynthesis in P. piscipula is consistent with maintaining a canopy …