Integrated agronomic practice increases maize grain yield and nitrogen use efficiency under various soil fertility conditions

Integrated Soil–Crop System Management with Organic Fertilizer Achieves Sustainable High Maize Yield and Nitrogen Use Efficiency in Northeast China Based on an 11-Year Field Study

“…In this study, the FP treatment might lead to degraded SOC and imbalanced soil nutrients by solely applying inorganic fertilizers with more N and P but less K. In addition, continuous shallow rotary tillage in the FP treatment could generate a hard plow pan at a soil depth of 15-20 cm, easily causing increased bulk density and decreased hydraulic conductivity and infiltration rate. These changes in soil physical properties limited root growth and extension and further reduced the capture of water and nutrient from deeper soil layers [17,35]. Under such circumstances, soil physic-chemical properties and nutrient supply in the FP treatment are insufficient to sustain high crop yields and nutrient uptake, and thus showed little yield improvement over years and larger variation during the experimental period.…”

“…In this study, the lower plants density (55,000 plants ha −1 ) in the FP treatment promoted individual plant growth with a larger ear with more kernels (mean = 550 kernels ear −1 ), but kernel number per unit area was still significantly lower than those in ISSM and HY. On the other hand, lower planting density can decrease leaf area index and light interception rate of plant population, thereby reduced photosynthetic capacity and plant DM accumulation [17,37]. Therefore, the lower source strength and smaller sink size (lower kernel number per unit area) concurrently limited biomass distribution towards grain (lower HI) and resulted in lower grain yield in the FP treatment.…”

“…Overall, the combined application of organic and inorganic fertilizers is superior to sole inorganic fertilization to achieve sustainable high crop yield and efficient nutrient uptake, and it has been highly recommended for intensive cropping systems in Northeast China [40]. In addition to optimizing nutrient management, ISSM implemented subsoil tillage at a depth of 25 cm to break the hard plow pan and probably improved soil physical properties and water storage, consequently promoting root growth and nutrient uptake [17,41]. On the basis of improved soil properties and optimal nutrient supply, maize density in ISSM was increased to 70,000 plants ha −1 , which is within the appropriate density range of 67,000-75,000 plants ha −1 for maize in Northeast China [36,42].…”

“…In Northeast China, yield potential for rainfed maize was estimated as 15.4 Mg ha −1 [43]. Previous studies reported that grain yield over 15 Mg ha −1 could be obtained when planting density exceed 80,000 plants ha −1 in North China [17]. To maximize grain yields, plants density in HY treatment was designed as 80,000 plants ha −1 , on the basis of substantial nutrient inputs and higher fertilization frequency during the growing season.…”

“…The ISSM approach has been demonstrated to effectively improve grain yield and N use efficiency (NUE) of maize (Zea mays L.), rice (Oryza Sativa L.) and wheat (Triticum aestivum L.), and it also remarkably reduces reactive N losses (RNL) and greenhouse gas (GHG) emissions, based on a total of 153 site-year field experiments across the main agro-ecological regions of China [13]. Moreover, several short-term studies have been conducted to further understand the ISSM effectiveness in terms of yield components, plant dry biomass (DM) accumulation and N uptake dynamics and their pre-or post-silking ratios, root growth and distribution, estimated N balance, measured nitrate leaching and GHG emissions for various cereal crops as well as the double-cropping rotation system [3,[14][15][16][17]. To date, little information is available for the long-term ISSM effects on crop productivity and environmental impacts.…”