In order to maintain high yields and protect the environment, the replacement of chemical fertilizers with organic ones has received increasing attention in recent years. A 2-year field experiment (2015–2016) was carried out to assess the effects of substituting equal amounts of mineral fertilizer with organic manure on the yield, dry matter (DM), and nitrogen (N) uptake of spring maize (Zea mays L.) and on the mineral N (N_min) distribution in the soil profile. The treatments included chemical fertilizer; different amounts of maize straw, cow manure, and chicken manure; and an unfertilized control (CK). Compared with the chemical fertilizer treatments, equal amounts of substitutions with cow manure or chicken manure increased production, and a 25% nutrient substitution resulted in the best yield increase. Straw return had no effect on maize production, and 100% straw return resulted in reduced production. The N accumulation and DM content both exhibited a slow-fast-slow growth trend throughout the various growth stages, and the average N uptake and DM accumulation in response to the treatments followed the order of chicken manure > cow manure > chemical fertilizer > straw return > CK. The N_min content in the profile not only increased as the N_min application rate increased but also showed greater increases at certain depths than at the surface, indicating that excessive N led to leaching. These results suggest that an appropriate proportion of organic substitution not only provides enough nutrients but also improves the soil environment and leads to increased yields. This technique represents a practical method of continuously increasing production and reducing the risk of N leaching.

Potassium (K) plays an important role in maize yield, but K accumulation characteristics in high yielding maize is still not well documented. A two-year field experiment was conducted to investigate the K accumulation characteristics of high yield (HY)（>15 t ha⁻¹）spring maize compared with medium yield (MY)（10–15 t ha⁻¹), and low yield (LY)（<10 t ha⁻¹). The maximum K accumulation stage in maize appeared between V6 and V12 stage (LY, MY, and HY was 125.46, 138.05, and 146.22 kg ha⁻¹, respectively). Most of the K (94.27–97.13%) was accumulated during vegetative stages. HY exhibited a significantly higher K accumulation than either MY or LY. For different organs, the K remobilization amount of leaf was the highest, and the remobilization amount of stalk was the lowest, the K remobilization amount of leaf and stalk showed as HY < MY < LY, same as the total K remobilization amount, but the K remobilization amount of sheath and husk plus cob showed the opposite order. These results indicated that sufficient nutrient supply for maize can not only accumulate more K but also delay leaf senescence and maintain high photosynthetic activity, resulting in reduced K remobilization from vegetative organs, and reduced K loss in whole plant.

Appropriate nutrient management practices are the determinant factors for maintaining good plant growth and development. The combination of inorganic fertilizers and straw may affect soil available micronutrients. The goals of this study were to determine the effects of Si fertilizers under straw return conditions on Si accumulation, partitioning, and remobilization in spring maize (Zea mays L.). A two-year field trial was conducted to investigate Si content accumulation and remobilization in spring maize under straw return conditions in Jilin Province. We evaluated Si accumulation and remobilization using four treatments: JS3 (straw return + 45 kg/hm² silicon), WS3 (no straw return + 45 kg/hm² silicon), JS0 (straw return + no silicon) and WS0 (no straw return + no silicon).The experimental results showed that the highest Si accumulation stage in maize occurred between the VT and R2 stages. The JS3 treatment accumulated 20.8% and 32.1% more Si, on average, than did the WS3 and WS0 treatments, respectively, at this stage. Different organs showed the same accumulation trend as the whole maize plant, but the Si remobilization amounts in distinct organs were the highest in the WS0 treatment. The total Si contribution to the grain in the WS0 treatment was 42.2% and 104.6% higher, on average, than those in the WS3 and JS3 treatments, respectively.This outcome showed that silicon fertilizer application could significantly increase silicon accumulation in maize plants and organs. Silicon fertilizer combined with straw returning not only further increased silicon accumulation but also reduced Si remobilization from the vegetative organs.