2). Dry root weight

in the 0–20 cm soil layer peaked at 14 d after pollination, and at 28 d for soils 20–40 cm and below. In the N0 treatment, dry root weight in the 0–20 cm layer peaked 14 d after pollination, but below 20 cm the dry root weight was reduced. Compared with N1, the N0 treatment showed a significant (P < 0.05) decrease in dry root weight at 0–20 cm soil depth, but there was a significant (P < 0.05) increase in the 70–100 cm layer. Changes in dry root weight in the 20–40 cm and 40–70 cm soil layers were not significantly different; however, the deep root ratio of N0 was significantly higher than that of N1. http://www.selleckchem.com/products/bmn-673.html Root reductive activity is a comprehensive index that reflects root absorption function [13]. After pollination, root reductive activity in each soil layer changed as the plants matured (Fig. 3), exhibiting single-peak increases

before decreasing. Under N1, root reductive activities underwent significant increases in the 0–20 cm and 20–40 cm soil layers, with peaks exhibiting prolonged durations. Root reductive activity in the 70–100 cm layer under N0 showed a steady decrease compared with N1. Under both nitrogen levels, root reductive activity decreased in each layer of closely spaced plants, and the greatest difference between treatments was observed during the grain-filling Ceritinib purchase stage. At late grain filling, differences were not as evident. The effects of different plant spacing treatments on maize grain yield are influenced by interactions between aboveground and belowground resource competitions. Compared with competition for light aboveground, nutrient competition in roots includes more than 20 nutrient elements, which have

substantial differences in molecular weight, soil oxidation state and mobility, and there are more significant effects of nutrient competition in roots on the growth of plant [8]. Narrow spacing is chosen most often to increase photosynthetic capacity by increasing the interception of available solar radiation, resulting in improved maize yield [6]. However, some studies have Megestrol Acetate demonstrated that an increase in solar radiation does not increase but decrease maize production [23] and [24]. In this study, excluding interference due to aboveground competition for light, narrow spaced plants significantly decreased aboveground dry matter accumulation and grain yield by 8.4% and 5.0%, respectively. Aboveground dry weight and grain production are closely related to nitrogen accumulation, translocation and utilization. Above-ground nitrogen accumulation in the narrow plant spacing treatment was decreased by an average 12.8%.