Micronutrient Knowledge Base

Purpose The effects of microbes and agrochemicals on crop plants are previously reported via seed treatments. We know little about the impacts of fungicides and microbial seed treatments on soybean shoot and root traits. Methods We investigated the effects of separate consortia of two plant growth-promoting rhizobacteria (PGPR) such as Bacillus simplex R180 and Burkholderia ambifaria C628, two Fusarium species (Fusarium oxysporum and Fusarium graminearum) (Fusarium), and Fungicides seed treatments on soybean traits. Results and Conclusions The PGPR and Fusarium increased and reduced the root and shoot dry mass of soybean plants, respectively. Fusarium infected plants had a relatively higher trichome leaf density followed by the PGPR, Control, Fungicide + PGPR, and Fungicides treatments. The PGPR increased P contents, while Fusarium reduced Mg and Mn contents of soybean shoot tissues. The nutrient contents of large and fine roots also varied across the seed treatments. Overall, fine roots showed higher mineral contents than large roots. Soybean roots showed relatively higher mineral contents such as Mg, Zn, Ca, Mn, Cu, B, Fe, and Mo in the fungicide + PGPR and fungicide treatments. Root K contents were substantially higher in the microbial than chemical treatments. The reduced and increased trichome density as well as tissue P contents in response to the Fungicides and microbial (PGPR, Fusarium) treatments, respectively, suggest the negative and positive effects of fungicides and microbes on soybean root and shoot traits. In conclusion, chemicals, pathogenic and beneficial microbes may influence plant shoot and root traits that are important for plant growth and development. Keywords Seed treatments · Probiotics · Fungicides · Rhizobacteria · Fusarium · Soybean · Root chemistry · Root system architecture

Providing an adequate supply of essential plant nutrients has a major impact on crop yields and is one crop production factor that can be readily managed. The purpose of this guide is to provide an overview of soil fertility practices in Manitoba and general fertilizer use considerations. Producers are encouraged to use this information in conjunction with reliable soil tests, their own experience and, when required, the assistance of a professional agronomist to develop effective, environmentally sound and economically viable fertilizer management practices. Five key practices must be implemented to achieve this goal: ■ apply only those nutrients that will result in economic yield increases ■ apply appropriate nutrient rates ■ apply appropriate sources of fertilizer nutrients ■ apply nutrients at appropriate timing ■ apply using the most effective and practical application techniques Practices that are economically effective and practical will serve to minimize potential adverse effects on the quality of soil and water resources.

Plant analysis is an excellent “quality control” tool for growers interested in high-yield crop production. It can be especially valuable for managing secondary and micronutrients that don’t have high quality, reliable soil tests available, and for providing insight into how efficiently you are using applied nutrients. Plant analysis can be used by Kansas farmers in two basic ways: for diagnostic purposes, and for monitoring nutrient levels at a common growth stage. Diagnostics can be done any time, and is especially valuable early in the season when corrective actions can easily be taken. Monitoring is generally done at the beginning of reproductive growth.

A field experiment was conducted during rainy seasons of 2003-04 and 2004-05. Fourteen treatments consisting of two fertility levels (50% and 100% recommended NPK) and their combination with FYM and supplementary nutrients viz. boron and iron besides control were tested in randomized block design with three replications. The results revealed that soybean yield attributed to cumulative effect of yield attributes viz., pods/ plant, seeds/pod and hundred seed weight were increased significantly by the addition of micronutrients and FYM at both the fertility levels (50% and 100% NPK). Integrated use of FYM (10.0 t/ha) and micronutrients viz., boron (2.0 kg/ha) and iron (5.0 kg/ ha) with inorganic NPK can replace up to 10 kg N, 30 kg P2O5 and 20 kg K2O/ha. Mean relative growth rate (RGR) and net assimilation rate (NAR) and leaf area index (LAI) were significantly affected by supplementation of inorganics (50% and 100% NPK) with FYM and/or micronutrients viz., boron and iron. Application of FYM, boron and iron along with inorganic fertilizer (50% and 100% recommended NPK) also significantly increased the root dry biomass, number of nodules, dry weight/plant and leghaemoglobin content at 60 days stage. Net returns and benefit: cost ratio was highest where boron (2.0 kg/ha) was applied with 100 % NPK and lowest in control (Inoculated). Highest protein and oil content and yield were recorded with RDF + FYM. Application of FYM, Fe and B with both 50 and 100% recommended fertilizers (RDF) markedly improved the content of unsaturated fatty acids (linolenic, linoleic and oleic) and reduced the content of saturated fatty acids (palmitic and stearic). Use of organic sources and micronutrients helped in maintaining soil fertility in terms of available nutrients and fertility balance. It was concluded that application of FYM and micronutrients viz., Fe and B along with 100 % NPK was essential for higher productivity and profitability of soybean as well as maintaining soil fertility. Key words: Glycine max , Grain yield, Quality, Integrated nutrient management, Leghaemoglobin, Nutrient balance, Residual soil fertility.

Nanoparticles (NP) are being introduced into agriculture as biopesticides and biofertilizers. There are hypotheses that micronutrients may have a more pronounced effect in the form of NP. This study aimed to investigate the potential of micronutrient NP in controlling Meloidogyne javanica in soybean. Experiment 1 comprised two trials conducted in pots in a greenhouse to assess the effect of ZnO, MnO, and FeO NP, their bulk equivalents, and sulfate salts on nematode control and soybean development. Zn reduced the number of nematode eggs per gram of root by approximately 40% relative to the control, regardless of the sources. In Experiment 2, two trials were performed to evaluate the effect of different doses and sources of Zn on nematode reproduction and crop development. Overall, ZnO NP did not differ from other Zn sources (Trial 1). In Trial 2, it was estimated that the maximum control (42.10%) would be obtained with 1087 mg L− 1 ZnO NP. At a dose of 500 mg L− 1, ZnO NP resulted in a greater reduction (48.21%) in total number of eggs than ZnSO4 and bulk ZnO. Experiment 3 was conducted to assess the effect of optimal doses of Zn on the lignin content of soybean roots. Lignin content increased under ZnO NP and bulk ZnO treatments. It was concluded that Zn helps reduce M. javanica reproduction on soybean, with ZnO NP having a similar action to their bulk counterpart. These effects are believed to stem from an increase in root lignin content, hindering nematode activity. Keywords Iron · Lignin · Manganese · Metallic nanoparticles · Root-knot nematodes · Zinc