Spatial Distribution Characteristics Of Root Of Rice And Maize And Cultivation Regulation

The growth and distribution of crop leaf and roots determines the nutrient uptake and photosynthetic capacity to a large extent. To clarify the characteristics of the canopy and the characteristics of root architecture of the crop and the influence with different cultivation measures, pot experiments were conducted to study the characteristics of the canopy and root architecture and difference between varieties. This research used the3D digitizer measured the3d coordinates of the leaf and roots at elongation stage and grain filling stage, ZhengDa619corn and XieSi corn as the material.On this basis,pot experiments were conducted to study the influence for canopy and root architecture with different N-fertilizer treatments, ZhengDa619corn as the material. On the same time, field root box experiment were conducted to study the characteristics of root architecture of the rice and the influence with different water management and N-fertilizer treatments and rice straw returning, the3d coordinates of the roots by hand measured, Jin You253as the material.1.The characteristics of the canopy and root architecture of maizeThe maize roots consisting of three parts:roots less than lmm diameter, roots between1to2mm diameter and more than2mm diameter. The total roots were composed of80%the roots less than lmm diameter, less than3%more than2mm diameter,9%-13%roots between1to2mm diameter. The total roots area composed of50%the roots less than lmm diameter,10-15%more than2mm diameter,25%-33%roots between1to2mm diameter. The total roots volume composed of20%-22%the roots less than lmm diameter, more than40%more than2mm diameter,30%-40%roots between1to2mm diameter. Therefore, the roots between1to2mm diameter was the main part of maize roots’ length and area, and the roots more than2mm was the main part of maize roots’ volume.The roots longitudinal length can reach55cm-75cm and transverse length can reach40cm-60cm,per plant total roots length can reach5000cm and19000cm at elongation stage and grain filling stage. Among them, about49.7%and20.7%of roots distribution in top20cm soil layer,and64.6%and43.7%of roots distribution in horizontal range of20cm.The change in total root length with the distance of root transverse distribution and longitudinal distribution could be mathematical simulated by Logistic model.(x:the transverse or longitudinal distance, Y:root cumulative length)The result shows that the maize leaf area were increased with growing process and reached maximum in grain filling stage. The longitudinal distribution of cumulative leaf area with regularities. The distribution of leaf area in each layer is evenly in addition to the bottom layer. Dynamic distribution of the cumulative leaf area in longitudinal distribution according to the Logistic model. The point of curve inflection shows the concentrated region of the whole leaf areas. The results shows that the angle between leaf and stem and the leaf drooping angle and average leaf distance were increased with growing process. The leaf orientation value was decreased. The leaf base-top distance and the leaf surface curvature increased at first but later decreased.2.The effect of the canopy and root architecture of maize under the different N-fertilizer treatmentsThe shows that the significant effect in the maize roots quantity, length, area and volume in different N-fertilizer treatments. The maize roots length, area and volume all significant decreased in elongation stage, but significant increased in grain filling stage with heavy panicle fertilizer treatment. On the basis of the same volume of nitrate fertilizer application on terms,heavy panicle fertilizer reduced the fertilizer usage in earlier growing stage and bring on the roots length, area, volume decreased. The other way round, heavy panicle fertilizer increased the fertilizer usage in later growing stage, bring on the roots length, area and volume increased. in grain filling stage. The effect was different for the roots with different diameter in different N-fertilizer treatments. The heavy panicle fertilizer treatment increased the roots area,volume ratio between in0-2mm diameter is highest.The shows that the effect is significant for the maize canopy in different N-fertilizer treatments. From the dynamic distribution of the leaf area, we can see that the different N-fertilizer treatments significant affected the leaf area. The leaf area is highest in heavy base fertilizer. The leaf area is lowest in elongation stage in heavy panicle fertilizer, but the leaf area was rapid growth in late growing stage. The different N-fertilizer treatments significant effected the leaf area longitudinal distribution in grain filling stage,heavy panicle fertilizer significant increased the leaf area in upper part region. The different N-fertilizer treatments effected the leaf spatial distribution and leaf shape. The leaf base-top distance and leaf angle were in especial. heavy panicle fertilizer increased The leaf base-top distance and leaf angle in late growing stage.3.The major different for the canopy and the characteristics of root architecture of ZhengDa619corn and XieSi cornIt is significant different between different varieties roots growth. ZhengDa619’s roots length, roots mean diameter, roots surface area, volume all lower than XieSi maize’s in elongation stage, but ZhengDa619’s roots length, roots mean diameter, roots surface area, volume all higher than XieSi maize’s in grain filling stage.Meanwhile, ZhengDa619roots between0-2mm diameters each biomass significant higher than XieSi maize’s.It’s shows that ZhengDa619’ roots growth than XieSi maize in late growing stage.It is significant difference in canopy in different plant type maize. First, ZhengDa619’s leaf area significant lower than XieSi’s in each stage, and the leaf longitudinal distribution is significant difference each other. ZhengDa619’s leaf longitudinal distribution is more uniformly. It is beneficial to improved the canopy architecture and population photosynthetic capability. Secondly, ZhengDa619’s leaf shape is different XieSi’s. ZhengDa619’s leaf angle and the leaf orientation value higher than XieSi’s,but the leaf drooping angle, average leaf distance, leaf drooping angle and leaf base-top distance is lower than XieSi’s. It’s shows that the ZhengDa619’s leaf shape is more compact and stand firm.4..The characteristics of root spatial distribution of rice and the effect of root architecture under the water managementThe results showed that about88%of roots were distributed in the top10cm soil layer, and60-70%of roots were distributed in horizontal range of10cm from the plant at tillering and maturity stages. The change in total root length with the distance of root horizontal distribution or the depth of root vertical distribution could be simulated by the equation Y=a (1-bx)(x:the transverse or longitudinal distance, Y: root cumulative length)Water management had impact on rice root vertical distribution and root number, but did not affect root horizontal distribution. Rice roots were0.6cm and3.5cm deeper,19.8%and26.4%longer, and28.3%and21.0%more under intermittently flooded irrigation than wet irrigation and continuously flooded irrigation, respectively.The shows that the effect is different to rice growth by different rice straw returning.the root length, dry weight by higher rice straw returning were higher than the lower rice straw returning’s in different stage,and roots longitudinal distribution also higher than the lower’s. It is also improve more roots distributed in shallow depth soil layer.