The efficient nutrient management is essential for agricultural green development. With the increase of farm land scale and the development of agricultural mechanization, the mismatch between agricultural machinery and agronomy in nutrient management becomes increasingly obvious. There is a requirement to coordinate agronomic techniques and machinery operation. This paper analyzed the current situation and improvement direction in nutrient management techniques and agricultural machinery in the cropping system of spring maize in northeast China, winter wheat-summer maize in north China, and rice planting system in south China. It is indicated that efficient fertilizer application technology needs suitable fertilizer application machinery as guarantee, new fertilizer products need new fertilizer application machinery, changing cultivation and tillage methods generates new demand for agricultural machinery, and fertilizer application mechanization to be upgraded by using information and automatic intelligent techniques. At the same time, the fertilizer products and fertilizer application technology innovation need to take into consideration of the feasibility of mechanization. This paper described the research progress of starter fertilizer, synchronized fertilizer application and sowing technology, and straw mulching strip tillage technology in maize, within-season mechanized fertilizer application technology in wheat, mechanized side-depth fertilizer application technology in rice, and mechanized variable fertilizer application technology in China. The suggestions were provided to enhance the integration of agricultural machinery and agronomic technology, so as to upgrade the level of nutrient management of field crops.

Intercropping of maize (Zea mays L.) and peanut (Arachis hypogaea L.) often results in greater yields than the respective sole crops. However, there is limited knowledge of aboveground and belowground interspecific interactions between maize and peanut in field. A two-year field experiment was conducted to investigate the effects of interspecific interactions on plant growth and grain yield for a peanut/maize intercropping system under different nitrogen (N) and phosphorus (P) levels. The method of root separation was employed to differentiate belowground from aboveground interspecific interactions. We observed that the global interspecific interaction effect on the shoot biomass of the intercropping system decreased with the coexistence period, and belowground interaction contributed more than aboveground interaction to advantages of the intercropping in terms of shoot biomass and grain yield. There was a positive effect from aboveground and belowground interspecific interactions on crop plant growth in the intercropping system, except that aboveground interaction had a negative effect on peanut during the late coexistence period. The advantage of intercropping on grain came mainly from increased maize yield (means 95%) due to aboveground interspecific competition for light and belowground interaction (61%–72% vs. 28%–39% in fertilizer treatments). There was a negative effect on grain yield from aboveground interaction for peanut, but belowground interspecific interaction positively affected peanut grain yield. The supply of N, P, or N + P increased grain yield of intercropped maize and the contribution from aboveground interspecific interaction. Our study suggests that the advantages of peanut/maize intercropping for yield mainly comes from aboveground interspecific competition for maize and belowground interspecific facilitation for peanut, and their respective yield can be enhanced by N and P. These findings are important for managing the intercropping system and optimizing the benefits from using this system.