Effects Of Cultivation And Management Modes On Soil Nutrient Supply Capacity And Nutrient Use Efficiency Of Summer Maize

The field experiments were conducted in 2013~2014 at two locations of high and low soil fertility in Dawenkou Town, Tai’an, Shandong Province(35°58′10N,117°03′30E). Summer maize variety ZhengDan 958 was used as experimental material. There were 7 cultivation modes, which combined modified fertilization management and planting density, including super high-yielding cultivation(SH), high-yielding and high efficiency cultivation(HH), local farmer’s practice(FP), and the controls which modes on the basis of high-yielding and high efficiency cultivation mode without input of N fertilizer(N0), K fertilizer(K0), P fertilizer(P0), or any fertilizer(N0K0P0), respectively. The experiments focused on the effects of different modes on nutrient supplying capability of soil, grain yield, biomass and nutrient use efficiency, with the aim of proposing technological approaches to enrich soil fertility and promote nutrients utilization efficiency on summer maize. The main results were as follows: 1. Effects of cultivation and management modes on soil physical propertiesSH and HH treatments could decrease soil bulk density and increase soil porosity and field capacity in 0~20 cm and 20~40 cm soil layer, so significantly improved the soil physical properties. NPK fertilizer combined with organic fertilizer could prevent soil acidification, to a certain extent, increased the value of soil pH, and promoted the formation and stability of large soil aggregate and increased the content of organic matter and total nitrogen in 5~2 mm soil aggregate and their contribution to organic and nitrogen content of soil. 2. Effects of cultivation and management modes on soil chemical propertiesWithout applying N, P or K fertilizer, the content of soil total N, P or K in the 0~40 cm soil layer would reduce, but the effect was not significant, while the content of soil available N, P or K in arable layer would be significantly decrease. SH and HH treatments, by applying NPK fertilizers and postponing the application of supplementary fertilizers, could promote the content of soil total and available nutrient and organic C and N in arable layer. The improveed effect of NPK fertilizers combined with organic fertilizer on soil properties was more significant than other treatments. 3. Effects of cultivation and management modes on grain yield and yield components of summer maizeCompared with HH, decreases in grain numbers per ear and grain weight were observed in all control treatments, especially significant reduce in N0 and N0K0P0 treatments, their grain yield reduced by 18.44% and 26.07%, respectively. These results indicated that N fertilizer is main limiting factor on grain yield of summer maize. Applying N fertilizer combined with P and K fertilizer was most important for high grain yield. SH and HH obtained 11.9% and 8.24% higher grain yield than FP treatment, respectively. Both SH and HH treatments could effectively decrease the reductions of grain numbers per ear and grain weigh by increasing planting density, and then grain yield would increase. 4. Effects of cultivation and management modes on the accumulation and distribution translocation of dry matter of summer maizeN fertilizer was main limiting factor on biomass of summer maize. The appropriate N, P and K fertilizers could promote dry matter accumulation of summer maize. SH and HH treatment could significantly increase the weight of maximum population dry matter accumulation rate, the rate of maximum accumulation and final the amount of population dry matter accumulation, especially dry matter accumulation in post-anthsis. The dry matter accumulation in post-anthsis were 29.25% and 23.65% higher for SH and HH than FP treatment. With increasing planting density and amount of fertilizer application and postponing N application could dramatically increase the proportion of dry matter accumulation in grain and obtain high yield. 5. Effects of cultivation and management modes on nutrient utilization of summer maizeDue to the input of too much chemical fertilizer, N, P and K accumulation of SH treatment were significantly higher than other treatments, but the uptakes efficiency(UPE), harvest index(HI) and Partial factor productivity(PFP) of N, P and K for SH were significant lower than other treatments. HH treatment had significantly higher UPE and PFP of N, P and K than those of SH treatment, which would benefit for achieving synchronization between high yield and high nutrient efficiency via appropriate fertilization management(variety of fertilizers, application rate and timing) and planting density.