European Journal of Agronomy

In Rodriguez et al. we quantified the effect of grain legume-cereal intercropping on the use of nitrogen resources in temperate agroecosystems, focusing on symbiotic nitrogen fixation and soil-derived nitrogen acquisition using a meta-analysis.

Twenty-nine accessions of two buckwheat species (Fagopyrum esculentum Moench (common buckwheat) and Fagopyrum tataricum (L.) Gaertn. (Tartary buckwheat) were evaluated for their allelopathic potential against two resistant weeds, i.e. the monocot Lolium rigidum Gaud. and the dicot Portulaca oleracea L. The bulking use of synthetic herbicides and their consequent contamination of the environment and resulting increment of resistant weeds, imminently requires a solution to achieve sustainable weed management without the use of chemical inputs. The results obtained in this study suggest that buckwheat accessions can sustainably manage weeds through plant interference as competition or allelopathy. This research showed that accessions differ in their potential for sustainably manage both weeds, with F. esculentum accessions being more effective against L. rigidum and F. tataricum accessions against both, monocot and dicot weeds. The chemical profile of buckwheat accessions was evaluated to know the content of polyphenols in common and Tartary buckwheat accessions and to know more about their ability to sustainably manage weeds. Differences in the chemical profile between the two buckwheat species were clear. While common buckwheat accessions showed more orientin, vitexin and hyperoside, Tartary buckwheat accessions had higher amounts of rutin, quercetin and kaempferol. We propose that the screening and selection of accessions with strong polyphenol content and vigorous growth can be a step towards organic farming due to its relation to the weed management.

Severe water scarcity necessitates the development of a scientifically informed basis for efficient crop irrigation.Both irrigation and crop planting pattern (the planting dates and the planting ratio for male to female maizeinbred lines) affect the yield components in hybrid maize production. A high kernel weight, which affects seedgermination, is critical in maize seed production. Therefore, the aim of this study was to build a system thatjointly optimizes irrigation and planting pattern (JOIPP) to guarantee a suitable kernel weight, maximizes yield,and saves water. The JOIPP was based on a model which could simulate flowering, predict kernel number andestimate the upper and lower limits of kernel weight based on the evapotranspiration and planting pattern.Parameters in JOIPP were calibrated and validated using data from experiments conducted from 2014 to 2016 inHexi Corridor, northwestern China. A weighted sum method was used to maximize yield and minimize irrigation.A genetic algorithm with a modified initial population generation module was used to solve this optimizationproblem. Results showed that when the minimum lower limit of kernel weight (LowKWmin) increased,there was decreased irrigation at the flowering stage, increased irrigation at the grain-filling stage, less optimalyield and water use efficiency when the available water insufficient. However, the associated risk of seed germinationfailure decreased. The optimized planting pattern, compared with the crop planting pattern used bylocal farmers, increased yield by about 10% and water use efficiency by about 7.3% when LowKWmin was260 mg/kernel. JOIPP is a useful tool that enables farmers and seed companies to save water and improve yieldand seed quality when planting and irrigating maize for hybrid seed production.