[Effect of reducing N and regulated fertilization on N loss from wheat-maize rotation system of farmland in Chao soil region of North China Plain].

The application of large amounts of nitrogen (N) fertilizer can result in soil N accumulation and consequently N loss. To address these problems in a wheat-maize rotation area of the North China Plain, a two-year field experiment (2016-2017) was conducted to examine the effects of three different N fertilizer strategies on crop yield, N uptake, N loss and soil inorganic N content. The treatments were: controlled-release fertilizer, microbial fertilizer, nitrification inhibitor and farmer's practice (control).

[Meta-analysis of stable carbon and nitrogen isotopic enrichment factors for aquatic animals].

Isotopic enrichment factor (Δ, the difference between the δ value of food and a consumer tissue) is an important parameter in using stable isotope analysis (SIA) to reconstruct diets, characterize trophic relationships, elucidate patterns of resource allocation, and construct food webs. Isotopic enrichment factor has been considered as a constancy value across a broad range of animals. However, recent studies showed that the isotopic enrichment factor differed among various types of animals although the magnitude of variation was not clear.