Influence of long-term fertilization on soil microbial biomass, dehydrogenase activity, and bacterial and fungal community structure in a brown soil of northeast China

Evaluation of vegetable-faba bean (Vicia faba L.) intercropping under Latvian agro-ecological conditions

BACKGROUND

Monoculture is used mostly in conventional agriculture, where a single crop is cultivated on the same land for a period of at least 12 months. In an organic and integrated growing approach, more attention is paid to plant-environment interactions and, as a result, diverse growing systems applying intercropping, catch crops, and green manure are being implemented. Thus, field experiments for evaluation of vegetable/faba bean full intercropping efficiency, in terms of vegetable and faba bean yield and protein content, were set up during two consecutive growing seasons (2014 and 2015).

RESULTS

Data obtained showed that the most efficient intercropping variants were cabbage/faba bean (cabbage yield 1.27-2.91 kg m^-2 , immature faba bean pods 0.20-0.43 kg m^-2 ) and carrot/faba bean (carrot yield 1.67-2.28 kg m^-2 , immature faba bean pods 0.10-0.52 kg m^-2 ), whilst onion and faba bean intercrop is not recommended for vegetable growing since it induces a very low onion yield (0.66-1.09 kg m^-2 ), although the highest immature faba bean pod yield was found in the onion/faba bean intercropping scheme (up to 0.56 kg m^-2 ).

CONCLUSION

Vegetable/faba bean intercropping can be used in practical horticulture for carrot and cabbage growing in order to ensure sustainable farming and environmentally friendly horticultural production. © 2017 Society of Chemical Industry.

Plant-microbial interactions in agriculture and the use of farming systems to improve diversity and productivity

A thorough understanding of the services provided by microorganisms to the agricultural ecosystem is integral to understanding how management systems can improve or deteriorate soil health and production over the long term. Yet it is hampered by the difficulty in measuring the intersection of plant, microbe, and environment, in no small part because of the situational specificity to some plant-microbial interactions, related to soil moisture, nutrient content, climate, and local diversity. Despite this, perspective on soil microbiota in agricultural settings can inform management practices to improve the sustainability of agricultural production.

Response of Bacteria Community to Long-Term Inorganic Nitrogen Application in Mulberry Field Soil

The bacterial community and diversity in mulberry field soils with different application ages of inorganic nitrogen fertilizer (4Y, 4-year-old; 17Y, 17-year-old; 32Y, 32-year- old) were investigated using next-generation sequencing. The results demonstrated that the application ages of nitrogen fertilizer significantly altered soil bacterial community and diversity. Soil bacterial Shannon diversity index and Chao 1 index decreased with the consecutive application of nitrogen fertilizer, and the 4Y soil exhibited the highest bacterial relative abundance and diversity. Of 45 bacterial genera (relative abundance ratio of genera greater than 0.3%), 18 were significantly affected by the plant age, and seven belong to Acidobacteria. The relative abundances of Acidobacteria Gp 1, Gp4 and Gp6 in the 4Y soil were significantly lower than that of in the 17Y and 32Y soils. However, the relative abundance of Pseudononas sp. in the 4Y soil was significantly higher than that of in the 17Y and 32Y soils. Most microbial parameters were significantly affected by soil pH and organic matter content which were significantly changed by long-term application of inorganic nitrogen fertilizer.

Soil fungal community comparison of different mulberry genotypes and the relationship with mulberry fruit sclerotiniosis

Mulberry fruit sclerotiniosis is a common soil-borne disease. We hypothesize that there is a relationship between the incidence of mulberry fruit sclerotiniosis and the soil fungal community. Therefore four mulberry genotypes with different resistance to sclerotiniosis were selected to study their soil fungal community under the same condition. A total of 6 phyla and 93 genera were identified from all mulberry samples. Genera affected by genotype, cover, and genotype by cover interactions, were 23, 20, and 11, respectively. There were 10 genera that differed between the resistant cultivars and the susceptible cultivars. In addition, the relative abundances of Humicola and Mortierella in the resistant mulberry cultivars with the cover treatments were significantly higher than that of in the susceptible cultivars. However, the relative abundance of Sclerotiniaceae and Scleromitrula that may cause sclerotiniosis in the uncover treatments were significantly higher compared with the cover treatments. The results suggested that the genotype of mulberry has a significant impact on the soil microbial community that may result in differences in resistance to sclerotiniosis, and covering could reduce the relative abundance of Sclerotiniaceae or Scleromitrula.

Effects of Forest Age on Soil Fungal Community in a Northern Temperate Ecosystem

The polymorphisms of soil fungal rDNA Internal Transcribed Spacer regions were studied in Korean pine forests of various ages (10-100-year-old trees) by means of cloned libraries, and analyzed to determine the effects of the trees' developmental stage on soil fungal community structure. The obtained Shannon diversity index (H) and richness (S) indicated that the diversity of the soil fungal community increased significantly with the development of Korean pines (P < 0.05). In addition, cluster analysis (UPGMA) showed that the soil fungal community variety associated with differently aged Korean pines was higher than 50 %. The soil fungal community diversity correlated significantly with the N content and C/N ratio of the soil (P < 0.05). The results of this study indicate that the age of in Korean pine can affect soil fungal community by altering soil properties, which in turn could affect the nutrient cycling in the forest ecosystem.