Experimental Field Plots Research Articles

Ecological strategies of biological and chemical control agents on wildfire disease of tobacco (Nicotiana tabacum L.)

BackgroundTo investigate the ecological effects of chemical and biological control methods on tobacco wildfire disease, a plot field experiment was conducted to compare the control efficiency and mechanisms of a chemical pesticide (kasugamycin wettable powder, KWP) and a biological control agent (BCA) through high-throughput sequencing of bacterial 16S rRNA genes.ResultsThe results showed that the BCA displayed better performance in decreasing the disease index and morbidity of tobacco than the chemical pesticide. By monitoring the endophytic community within tobacco leaves, it was found that the control effects of these two methods might be mediated by different changes in the endophytic bacterial communities and community assembly patterns. The application of either method decreased the taxonomic diversity of the leaf endophytic community. Compared to the BCA, KWP showed a more significant effect on the endophytic community structure, while the endophytic community treated with the BCA was able to return to the original state, which presented much lower disease infection. The disease control efficiency of KWP and BCA treatments might be achieved by increasing the abundance of Sphingomonas and Streptophyta, respectively. Furthermore, an analysis of the ecological processes in community assembly indicated that the BCA strengthened the homogeneous and variable selection, while KWP enhanced ecological drift.ConclusionsThe results suggested different control mechanisms between KWP and BCA treatments, which will help in developing diverse ecological strategies for plant disease control.

Crop functional diversity drives multiple ecosystem functions during early agroforestry succession

Abstract We still lack practical guidelines for diversifying cropping systems that consider both yield and regulating functions of agroecosystems. Recent studies have suggested that maximizing functional diversity (FD, the distribution of species with different functional traits in the niche space) may lead to agroecosystems with greater multifunctionality due to niche complementarity. Therefore, scientists are now advocating the use of a trait‐based approach to develop multifunctional sustainable agroecosystems. In order to assess the effects of crop FD on key agroecosystem functions and to consider trade‐offs and synergies among them, we established, in late 2016, permanent experimental field plots of successional agroforestry systems (SAFS), in humid subtropical Southern Brazil. The experiment represents a gradient of plant functional trait diversity (designed FD based on leaf nitrogen concentration), while maintaining crop species richness constant across all treatments. Our hypothesis is that the observed FD of crops (hereafter, crop FD) drives multiple agroecosystem functions. We determined the observed FD by quantifying traits of crops and weeds (maximum plant height, leaf area, specific leaf area) and performed two data collections (March and September 2017) at the end of the summer and winter crops respectively. We used structural equation modelling to test a hypothetical causal model to explain how crop FD affects three functions: weed suppression, soil protection (soil cover by either crops or weeds) and crop yield. Our results support the hypothesis that high crop FD drives agroecosystem processes and contributes to the provision of multiple ecosystem functions. We found that with greater crop FD in SAFS, crop plants occupied a large niche space, thereby increasing the total photosynthetic light intercepted in the agroecosystem, that in turn, increased crop yield. Additionally, greater FD increased soil protection by crops and decreased weed cover. This greater FD also reduced the FD of the weed community. Synthesis and applications. Crop mixtures based on complementary plant traits can increase the multifunctionality of agroecosystems through their sustainable use. A more heterogeneous structure and projection of crop leaf area drives greater resistance to competition with weeds and produces higher crop yields in young diversified crop mixtures.

Nitrogen levels regulate intercropping-related mitigation of potential nitrate leaching

Intercropping improves yield and is broadly adopted worldwide; however, the risk and regulatory mechanism of nitrate leaching in intercropping compared with monocropping remain elusive. A fixed plot field experiment was conducted with three cropping patterns (maize monocropping, potato monocropping, and maize–potato intercropping) under four (nitrogen) N levels in Kunming, China during 2014–2017. Based on crop N uptake and soil nitrate transformation, the underlying mechanism of potential nitrate-N (NO3−-N) leaching (NO3−-N accumulation below the root layer) and N regulation was explored under intercropping and monocropping. The results showed that the area-scaled potential NO3−-N leaching under intercropping was mitigated by 3.4–37.4%, with a mean of 15.8% relative to the weighted mean of maize- and potato-monocropping. Intercropping-related mitigation of potential NO3−-N leaching was enhanced with increasing N level. Intercropping increased the ammonia-oxidizing archaea population and soil nitrification potential but had no significant impact on the abundance of ammonia-oxidizing bacteria and narG. Redundancy analysis and structural equation modeling indicated that soil water played a crucial role in regulating the intercropping-related mitigation of potential NO3−-N leaching, while the improvement in N uptake by intercropped maize reduced the potential NO3−-N leaching at low and medium N levels. The results highlight the intercropping advantage over monocropping in mitigating the risk of NO3−-N leaching. This study provides insights into the environmental impacts of diversified cropping systems and regulating mechanisms.

Accelerated Dissipation of Two Herbicides after Repeated Application in Field Experiments with Organically-Amended Soil

Organic wastes applied as composted amendments may improve the quality of degraded soils and modify the fate of pesticides. This work has set out to study the dissipation kinetics of the herbicides chlorotoluron and flufenacet during their second-year application in field experimental plots with a sandy-loam agricultural soil without amendment (S) and amended with spent mushroom substrate (S + SMS) or green compost (S + GC). The SMS and GC were applied to the soil during the previous winter’s wheat crop campaign (1 year before the second herbicide application) at rates of 140 and 85 t ha−1 (dry weight basis), respectively. The experiment involved randomized complete blocks with plots of 81 m2, including three replicates per soil treatment. Surface soils were sampled after herbicide application for 225 days, and herbicide residues in the soil samples were determined by HPLC-MS. The dissipation curves of both herbicides for the three soil treatments were better fitted to the first order multi-compartment (FOMC) kinetic model. The dissipation rates of the most hydrophobic herbicide, flufenacet, were slower than those for chlorotoluron in both unamended and amended soils. The half-life (DT50) values ranged between 20.7 to 41.1 days for chlorotoluron, and 42.9 to 75.6 days for flufenacet, and they followed the order S > S + SMS > S + GC. The DT50 values of chlorotoluron were close for S + SMS and S + GC, and the DT50 of flufenacet for S was similar to that for S + SMS. These DT50 values decreased up to four times with respect to those calculated after the first application indicating an accelerated dissipation of the herbicides after the second application especially in amended soil in comparison with unamended soil. The persistence of chlorotoluron and flufenacet in an agricultural soil was modified by the effect of the organic amendments, weather conditions, and possibly the repeated application of the compounds under real field conditions.

DRAINMOD modeling framework for simulating controlled drainage effect on lateral seepage from artificially drained fields

We demonstrated a DRAINMOD modeling framework to predict controlled drainage (CD) effect on the fate of water in artificially drained agricultural fields, which is key for determining the water quality benefits of the practice. To demonstrate this modeling framework, DRAINMOD simulated the hydrology of a subsurface drained grass field in Eastern North Carolina, U.S. under both free drainage (FD) and CD. Three scenarios were simulated for each water management: no lateral seepage (LS) and LS with constant and dynamic hydraulic head (Hr). For each scenario, predicted water table depth (WTD) and subsurface drainage were compared to observed values using Mean Absolute Error, Nash-Sutcliffe Efficiency, and Normalized Percent Error. Predicted water balance components for different scenarios were also investigated. Results clearly showed that LS was a significant component of the water balance for CD. Model predictions showed that 96% of the reduction in subsurface drainage due to CD could be attributed to LS (33.5 cm yr−1). The large values of LS predicted by the model were attributed to the presence of a permeable sandy layer in the soil profile, the shallow management depth of the drain outlet, and the small size of the experimental field plots. Agreement between predicted and observed WTD and subsurface drainage ranged from acceptable to excellent for FD with and without considering LS. In contrast, DRAINMOD simulations for CD yielded acceptable predictions only for the scenario considering LS with dynamic Hr. This study demonstrated the power of process-based simulation models, such as DRAINMOD, for interpreting and explaining data of experimental studies and underscored the importance of using a proper model calibration strategy for yielding reliable predictions. This study highlights the need for well-coordinated experimental and modeling research to further investigate how seepage affect CD performance for reducing drainage flow and nitrogen losses from artificially drained agricultural fields.

The Effect of Foliar Fertilization with Micronutrients on Disease Severity and Mycotoxin Concentrations in the Grain of Winter Spelt (Triticum aestivum spp. spelta L.): A Case Study

The effect of mineral fertilization (NPK), foliar fertilization with micronutrients (Cu, Zn and Mn) and the NanoGro biostimulant on the severity of leaf, spike, stem base and root diseases in winter spelt cv. Schwabenkorn was evaluated in a field-plot experiment. A mycological analysis was performed and the content of Fusarium mycotoxins in grain was determined. Mineral fertilization (NPK), foliar fertilization with micronutrients and the NanoGro biostimulant exerted varied effects on the severity of Septoria leaf blotch and Septoria glume blotch, they promoted the spread of brown rust (excluding the NPK + NanoGro treatment) and inhibited the spread of black head mold (excluding the NPK treatment), eyespot and Fusarium foot and root rot (excluding the NPK + Mn treatment). Fertilization had no influence on grain yield or the content of Fusarium mycotoxins in grain. The concentrations of deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEA) and fumonisins FB1 + FB2 did not exceed the maximum permissible levels (except for DON in NPK + Cu + Zn + Mn and NPK + NanoGro treatments). Throughout the experiment, ergosterol (ERG) concentrations were highest in the grain of unfertilized spelt plants.

Assessing the WEPP model performance for predicting daily runoff in three terrestrial ecosystems in western Syria

Soil erosion is one of the main threats facing the agriculture and natural resources sector all over the world, and the same is true for Syria. Several empirical and physically based tools have been proposed to assess erosion induced soil losses and runoff driving the processes, from plot to regional spatial scales. The main goal of this research is to evaluate the performance of the Water Erosion Prediction Project (WEPP) model in predicting runoff in comparison with field experiments in the Al-Sabahia region of Western Syria in three ecosystems: agricultural lands (AG), burned forest (BF) and forest (FO). To achieve this, field experimental plots (2∗1.65∗0.5 m) were prepared to obtain runoff observation data between September 2012 and December 2013. In addition, the input data (atmospheric forcing, soil, slope, land management) were prepared to run the WEPP model to estimate the runoff. The results indicate that the average observed runoffs in the AG, BF and FO were 12.54 ± 1.17, 4.81 ± 0.97 and 1.72 ± 0.16 mm/event, respectively, while the simulated runoffs in the AG, BF and FO were 15.15 ± 0.89, 9.23 ± 1.48 and 2.61 ± 0.47mm/event, respectively. The statistical evaluation of the model's performance showed an unsatisfactory performance of the WEPP model for predicting the run-offs in the study area. This may be caused by the structural flaws in the model, and/or the insufficient site-specific input parameters. So, to achieve good performance and reliable results of the WEPP model, more observation data is required from different ecosystems in Syria. These findings can provide guidance to planners and environmental engineers for proposing environmental protection and water resources management plans in the Coastal Region in Syria.

Effects of high dose copper on plant growth and mineral nutrient (Zn, Fe, Mg, K, Ca) uptake in spinach.

Loessal soil is one of the main cultivated soils in northwest China. Part of its distribution area was irrigated with industrial wastewater in past three decades. This caused heavy metal contamination in the soil. It had induced toxicity on crops and also threatened local human health for now. Based on a field plot experiment, effects of different Cu concentrations (from 45 to 2000 mg kg-1) in loessal soil on spinach plant growth and uptake of mineral nutrients (Zn, Fe, Mg, K, and Ca) by spinach were investigated. The Cu addition increased available concentrations of mineral nutrients in loessal soil and concentrations of Cu, Zn, Mg, and Ca in roots. The translocation of mineral nutrients from roots to leaves was inhibited under Cu addition, inducing their decrease in leaves. The EC10 and EC50 of soil Cu in relative dry weights of leaves were 240.33 mg kg-1 and 1205.04 mg kg-1, respectively. The PLS-PM analysis showed that available concentrations of nutrients in soil were only affected by Cu in soil positively, nutrients in roots were mainly affected by Cu in soil and Cu in leaves positively, nutrients in leaves were mainly affected by Cu in roots negatively, translocation of nutrients in spinach and plant growth were principally affected by Cu in leaves negatively, and the total effect of Cu in leaves on nutrients in roots and leaves, translocation of nutrients in spinach, and plant growth was the highest. Our results indicated that the phytotoxicity of Cu including spinach growth inhibition and mineral disorder in spinach was mainly affected by the Cu concentrations in leaves.

Isolation and characterization of antagonistic Paenibacillus polymyxa HX-140 and its biocontrol potential against Fusarium wilt of cucumber seedlings

ObjectiveThe aim of this study is to evaluate the efficacy of the strain Paenibacillus polymyxa HX-140, isolated from the rhizosphere soil of rape, to control Fusarium wilt of cucumber seedlings caused by Fusarium oxysporum f. sp. cucumerinum.ResultsStrain HX-140 was able to produce protease, cellulase, β-1,3-glucanase and antifungal volatile organic compounds. An in vitro dual culture test showed that strain HX-140 exhibited broad spectrum antifungal activity against soil-borne plant pathogenic fungi. Strain HX-140 also reduced the infection of Fusarium wilt of cucumber seedlings by 55.6% in a greenhouse pot experiment. A field plot experiment confirmed the biocontrol effects and further revealed that antifungal activity was positively correlated with inoculum size by the root-irrigation method. Here, inoculums at 106 107 and 108 cfu/mL of HX-140 bacterial suspension reduced the incidence of Fusarium wilt of cucumber seedling by 19.5, 41.1, and 50.9%, respectively.ConclusionsTaken together, our results suggest that P. polymyxa HX-140 has significant potential in the control of Fusarium wilt and possibly other fungal diseases of cucumber.

Selenium effect on wheat grain yield and quality applied in different growth stages

Small field plot experiments were carried out at the testing station of the Central Control and Testing Institute in Agriculture in Veľký Meder (Slovakia) in the experimental years 2014/2015, 2015/2016 and 2016/2017. Selenium salts in the form of sodium selenite and sodium selenate were applied in growth phases: end of tillering (BBCH 29) and flag leaf ligule and collar visible (BBCH 39). The effect of experimental years 2014/2015, 2015/2016 and 2016/2017 on the yield of wheat grain was not statistically significant within the observed variants. The achieved mean yields were in the range from 10.06 ± 0.81 to 11.07 ± 0.29 t/ha in 2014/2015, from 9.82 ± 0.54 to 10.32 ± 0.10 t/hain 2015/2016 and from 11.23 ± 0.76 to 11.64 ± 0.51 t/ha in 2016/2017. Selenate in comparison with selenite influenced the selenium accumulation in wheat grains more positively. However, a significant difference was recorded in variants with selenite application in the flag leaf growth phase in comparison with the end of tillering phase. The influence on the content of macroelements P, K, Ca and microelements Cu and Fe was observed in sodium selenite only; its application decreased the element content in comparison with the control variant. Statistically significantly higher values of fiber and fat were achieved after application of selenium in the flag leaf growth stage in comparison with the end of tillering.

Screening maize (Zea mays L.) varieties with low accumulation of cadmium, arsenic, and lead in edible parts but high accumulation in other parts: a field plot experiment.

To find maize varieties with both safe production and soil remediation, 11 maize varieties were planted in field soil which was combinedly polluted by cadmium (Cd), arsenic (As), and lead (Pb). The plant growth, accumulation, phytochemical forms, and translocation of Cd, As, and Pb in different tissues were examined. Furthermore, maize varieties with low metal accumulation in their edible parts but high accumulation in other parts were selected as remediation candidates and pollution-safe varieties. The results showed that the growth of varieties Yayu69, Longhuang2502, and Shennongyu10 were the least affected by heavy metals. The concentrations of Cd, As, and Pb in all of the tested maize grains met the national feed hygiene standards, and the grain concentrations of the three metals in Yayu69, Shengnongyu10, and Yunrui62 all met the national food safety standards. According to the extraction efficiency of Cd, As, and Pb and heavy metal concentrations in grains, four types of maize were classified as follows: (1) the first category was suitable for both soil remediation and safe production, including the varieties Yayu69 (Cd, Pb), Jinyi418 (As, Cd), and Shengnongyu10 (Pb); (2) the second category had a high concentration of metals in edible part but did not exceed the limiting value in national feed hygiene standards, and the metal extraction efficiency was also high, including Beiyu1521 (Cd) and Longhuang2502 (Cd, As, Pb); (3) the third category included heavy metal exclusion varieties with low metals accumulation, such as Yayu749 (Cd), Yunrui62 (As, Pb), and Yunrui8 (As); and (4) the fourth type covered risk maize varieties with food safety risks and unsuitable cultivation at sites polluted with toxic metals, including Chuangui1586 (Pb) and Enyu69 (As). The variety Yayu69 (a Cd/Pb low accumulator in grain) contained a low percentage of inorganic (FE) and water-soluble (FW) Cd (4%) and Pb (6%) in roots, respectively, but the percentage of FE and FW Cd and Pb in the variety Beiyu1521 (a Cd/Pb high accumulator in grain) was up to 29% and 13%. Our results provided a new perspective in applying maize varieties with different metal-accumulating ability in their different parts to achieve the remediation of metal-polluted soil and the sustainable development of agricultural production.

Assessment of Yield and Yield Components of Soya-Bean (Glycine Max (L.) Merril) Grown Under Conventional Agronomic Practices of Lesotho

An experiment on soya-bean cultivars was conducted in Lesotho at The National University of Lesotho, Roma, with the objectives of (i) establishing the differences among the soya-bean cultivars in terms of growth and yield parameters measured (ii) to estimate the regression coefficients for yield components (iii) determining correlation among traits that influence yield of soya-bean. Field plot experiment was laid-out in a completely randomized block design with 28 treatments and three replications. Data collected were 100 grain weight, plant height, number of pods per plant, leaflets size and leaflet shape. Data were subjected to analysis of variance, multiple linear regression and person’s correlation of coefficient. Results of analysis of variance revealed highly significant difference (P<0.001) among soya-bean cultivars for plant height, weight per plot and weight of 100 grains, while no significant differences were observed among leaf shape, number of pots per plant and leaf size. Regression analysis showed a highly significant (P<0.01) regression, implying that plant height contributed immensely on the yield of soya-beans followed by leaflets shape. Correlations among most parameters were high and few parameters were moderately correlated.

Early Effect of Pine Biochar on Peach-Tree Planting on Microbial Community Composition and Enzymatic Activity

Biochar offers several benefits as a soil amendment, including increased soil fertility, carbon sequestration, and water-holding capacity in nutrient-poor soils. In this study, soil samples with and without biochar additives were collected for two consecutive years from an experimental field plot to examine its effect on the microbial community structure and functions in sandy soils under peach-trees (Prunus persica). The four treatments evaluated consisted of two different rates of biochar incorporated into the soil (5%, and 10%, v/v), one “dynamic” surface application of biochar, and a 0% biochar control. Fatty acid methyl ester (FAME) analysis was used to assess the microbial community structure, and enzyme activities involved in C, N, P, and S nutrient cycling were used as a means of assessing soil functionality. Total FAME and bacterial indicators increased by 18% and 12%, respectively, in the 10% incorporated and 5% surface applied treatments. Biochar applications increased β-glucosaminidase and arylsulfatase activities, 5–30% and 12–46%, respectively. β-glucosidase and acid phosphatase activities decreased by approximately 18–35% and 5–22% in the 0–15 cm soils. The overall results suggest that biochar’s addition to the sandy soils stimulated microbial activity, contributing to the increased mean weight diameter (MWD), C sequestration, and consequential soil health. The changes in microbial community structure and functions may be useful predictors of modifications in soil organic matter (SOM) dynamics due to the long-term application of pine biochar in these systems.

Soil biota suppress maize growth and influence root traits under continuous monoculture

This study investigated maize-soil biota interactions as well as the soil legacy effects of continuous monoculture (CM) on maize performance. We conducted a glasshouse experiment that compared the performance of maize inoculated with living or sterilized soil inocula collected from experimental field plots with cropping histories of 1 to 5 years of continuous maize monoculture, where the soil type is Nicollet clay loam with moderate fertility. We measured the biomass, yield, root traits and leaf nutrients of maize as well as eukaryotic soil organisms. Inoculation with living soil dramatically reduced maize biomass and yield compared to inoculation with sterilized soil, showing CM to have strong negative soil biotic legacy effects on maize. Nonetheless, the strength of soil biotic effects on most maize variables were relatively stable over time under CM. The response of maize total biomass to living soil inoculation correlated positively with arbuscular mycorrhizal (AM) fungal abundance but negatively with soil fauna abundance, whereas it did not relate with the abundance of plant pathogenetic fungi or herbivorous nematodes. The roots showed acquisitive syndromes (high specific root length but low root diameter) in sterilized soil but conservative syndromes (opposite traits) in living soil. The responses in root system structure were tightly related with AM fungal diversity and community composition. Our study shows strong and stable negative effects of soil biota on maize under CM. The complex effects of soil biota on maize performance highlight the need to explore the functions of different groups of soil organisms to better understand and control negative soil legacy effects in agroecosystems.

Influence of Potassium Supply and Harvest Time on Selected Growth, Physiology, and Quality Factors of Ephedra sinica Stapf.

The present study aims to investigate the influences of potassium (K) supply and harvest time on selected growth, physiology and quality factors of Ephedra sinica Stapf (ESS). A field plot experiment was conducted under 10 levels of K supply (K1–K10, 0–538.3 kg ha−1). ESS was sampled randomly with uniform distribution locations of each plot on August 27 (H1), September 15 (H2), October 6 (H3), and October 27 (H4) in 2018. The late-harvested ESS had low SPAD value, peroxidase activity, cell membrane permeability, and high 10 cm stem weight, phenylalanine ammonia-lyase activity, free proline, ephedrine, total alkaloids, or flavonoids contents. The fertilizer dose of 59.8–239.3 kg ha−1 (K2-K5) increased the 10 cm stem weight, stem or root fresh and dry weights, the SPAD value, free proline content, peroxidase activity, reduced the root activity. The ephedrine, pseudoephedrine, total alkaloids, and flavonoids contents increased with the increase of K supply before K7 (358.9 kg ha−1). The harvest time influenced the increase of these quality factors resulting from one unit of K application. The harvested E. sinica in H3 increased the ephedrine content 85.97%, pseudoephedrine 21.53%, total alkaloids 38.02%, and total flavonoids 66.43%, compared with their average values of H1. The dose of 239.3 kg ha−1 (K5) reduced the ephedrine content 14.99%, pseudoephedrine 8.07%, total alkaloids 16.4%, and total flavonoids 28.71%, compared with K7, however increased the stem fresh and dry weight 163.21% and 125.70%, respectively. The late-harvested ESS had high contents of quality factors and good quality. The K dose of 239.3 kg ha−1 was appropriate for cultivated ESS high yield and quality accumulation.

Effects of Film Materials on Ammonia Volatilization Emissions from a Paddy System After Reducing Nitrogen Fertilizer Application

Ammonia volatilization emissions constitute the main pathway of nitrogen loss from paddy systems. Present control technologies are based on reducing the amount of nitrogen fertilizer applied. However, ratio of nitrogen loss through ammonia volatilization emissions has not changed, and it has become a bottleneck for promoting nitrogen use efficiency. Therefore, in order to study the effects of film materials on ammonia volatilization emissions, a two-year field plot experiment was carried out with agricultural waste powder and amphipathic molecule materials spread on surface water after nitrogen fertilizer application in paddy system. The results showed that film materials could reduce nitrogen loss through ammonia volatilization by 19%-31% in the paddy season, and this part of nitrogen was accumulated in soil or assimilated by paddy tissue. The ammonium concentration and pH in the surface water and film materials were the major control factors of ammonia volatilization emissions with nitrogen fertilizer application. Moreover, further reductions in ammonia volatilization emissions could be achieved by film materials after reducing nitrogen fertilizer application. Differences in the effect mechanisms of the film materials provide flexible options for practical agricultural production to meet demands.

Yuetian soil conditioner can enhance the output, decrease the concentration of heavy metals of areca taro and reduce soil acidity

The influences of using several dosages of Yuetian soil conditioner on the output, heavy metal concentration of areca taro and soil basic fertility characteristics were studied by field plot experiment. Outcomes indicated that the output of areca taro enhanced by 6.2%∼12.8%, As concentration decreased by 28.9%∼40.0%, Hg concentration decreased by 28.6%∼50.0%, soil pH value enhanced by 4.0%∼34.9%, exchangeable acid decreased by 10.5%∼95.2%, available phosphorus decreased by 36.4%∼54.6%, and the concentration of organic matter, hydrolytic nitrogen and available K was different, but the concentration of Pb, Cd and Cr enhanced, and the concentration of Hg and As was different.

Tebei calcium oyster powder may enhance rice output, decrease rice heavy metal concentration and reduce soil acidity

The influences of several doses of Tebei calcium oyster powder on rice output, heavy metal concentration and basic soil fertility characteristics were studied by field plot experiment. Outcomes indicated that the use of several doses of Tebei calcium oyster powder could raise the dry matter output of rice by 5.24%∼20.65%, reduce the Cd and Pb concentration of rice by 7.80%∼53.67% and 12.63%∼60.10%, raise the pH value of soil by 4.1%∼24.5%, decrease the exchangeable acid (potential acid) by 1.0%∼53.8%, and decrease the concentration of Influenceive Cd and Pb by 64.22%∼77.98% and 4.65%∼22.59%, respectively.

Screening and Safety Evaluation of Herbicides in Oat Field

In order to screen safe and efficient herbicide varieties and combinations suitable for oat field use, field plot experiment method was used to spray stems and leaves from 3 to 5 leaf stages of oat. The results showed that the control effects of single-dose treatment of 45.9% difluoro-dioctyl SC 450 mL/hm2 and 20% tribenuron-chlorofluoropyroxyacetic acid WP 900 g/hm2 on weeds in oat fields were all above 80%, herbicides 10% tribenuron-methyl WP 150 g/hm2, 42% 2-methyl·fluroxypyr EC 1125 mL/hm2, 48% bentazone AS 3000 mL/hm2 and 72% 2,4-D butylate EC 150 mL/hm2 mixed use, and 10% pyrazone WP 300 g/hm2 + 56% 2-methyl 4-sodium chloride WP 1200 g/hm2 + 50 g/L difluorsulphonamide SC 90 mL/hm2 mixed use of broad-leaved weeds in oat field control effect were more than 80%, significantly higher than the conventional herbicide used in production, 48% bentazone AS 3000 mL/hm2 + 72% 2,4-D butylate EC 150 mL/hm2 and 2-methyl·fluroxypyr EC 1125 mL/hm2 + 72%. The test results enriched the available herbicide varieties for chemical weeding in oat fields and could be applied in oat fields.

The Effect of Foliar Fertilization with Micronutrients on the Incidence and Severity of Leaf and Stem-base Diseases in Winter Triticale (x Triticosecale Witmm.) and Winter Rye (Secale cereale L.)

Winter triticale (Triticale) cv. Dinaro and winter rye (Secale cereale L.) cv. Dankowskie Diament were grown in 2012 and 2013 in a field-plot experiment in Tomaszkowo near Olsztyn (NE Poland). The experiment consisted of 7 treatments: absolute control (without fertilizers or the growth stimulator), control-NPK fertilizer, NPK fertilizer + micronutrients applied alone or in combination (4 treatments), NPK fertilizer + Nano-Gro growth stimulator. The severity of disease symptoms on the leaves and stem-bases of triticale and rye was evaluated throughout the growing season. Symptoms of powdery mildew on the leaves of winter triticale and winter rye were noted only in the growing season of 2013, and disease severity remained at a low level. In the growing season of 2012, weather conditions were conducive to the spread of Septoria tritici blotch (STB) and brown rust on triticale (the highest values of infection index were 41.6 and 23.8%, respectively), and scald and brown rust on rye (29.0 and 38.1%, respectively). Foliar application of micronutrients influenced the rates of infections caused by Zymoseptoria tritici and Puccinia recondita f. sp. tritici on triticale leaves. Symptoms of eyespot and Fusarium foot and root rot were noted on the stem-bases of both cereal species, whereas symptoms of take-all disease and sharp eyespot were observed sporadically. Significant differences were found between treatments in the severity of infections caused by Gaeumannomyces graminis on the stem-bases of triticale, and by Tapesia spp. and Rhizoctonia spp. on the stem-bases of rye.