The Effect Of Different Cultivation Patterns On Grain Yield And Nitrogen Use Efficiency Of Winter Wheat

The experiments were conducted with Tainong 18 in 2011-2013 wheat growing season in Dawenkou Town, Daiyue District, Tai’an, Shandong, P.R.China. Three cultivation patterns, including farming practice cultivation pattern(FP), super high yield cultivation pattern(SH), high yield and high efficiency cultivation pattern(HH), were set to explore the effect of different cultivation patterns on grain yield formation, Nitrogen use efficiency, nitrogen accumulation, nitrogen distribution, nitrogen translocation under different fertility levels. 1 The effect of different cultivation patterns on grain yield and its components.The effects of cultivation patterns were significant on the grain yield in different fertility levels. In low fertility level, the number of tillers per unit area of the SH pattern was higher than HH and FP at wintering and jointing significantly. The HH pattern has the maximum number of tillers per unit area at anthesis and maturity among the three cultivation patterns with the minimum number appearing in the FP pattern. In high fertility level, each pattern get their own maximum number of tillers per unit area at jointing stage and the number of the FP pattern was higher than the other two patterns significantly. With the advance of growing season, the number of tillers decreased. The biggest reductions was in the FP pattern. At anthesis and maturity stage, the SH pattern had the maximum number of tillers per unit area and FP got the minimum. The differences between different patterns reached significant level.The grain yield was affected by cultivation pattern significantly. The highest grain yield was observed in the SH pattern. Compared with the SH pattern, the grain yield of the HH pattern decreased, but it was higher than the FP pattern, maintaining at the high level. On the hand of the components of grain yield, equal kernel weight was observed among three cultivation patterns in low fertility level. The spike and kernels per unit area of the SH pattern increased significantly compared with the FP pattern. The HH pattern had higher spike per unit area than the FP pattern but there was no significant difference observed in kernels number among them. In high fertility, the SH pattern had the highest number of spike per unit area. In contrast to the FP pattern, the spike per unit area and kernel weight of HH pattern increased significantly. 2 The effect of different cultivation patterns on nitrogen use efficiency.The effect of different cultivation patterns on nitrogen use efficiency was significant. The NUE of the HH pattern was higher than the FP and SH pattern significantly in different fertility levels, SH pattern’s NUE was the lowest of all three cultivation patterns. Compared with the low fertility level, NUE of same cultivation pattern in high fertility level decreased significantly. The UPE followed the same trend with the NUE that the HH pattern has the highest UPE and the difference was significant. In 2012-2013 growing season, the UPE of the HH pattern in high fertility increased significantly compared with that in low fertility level. There was no significant difference observed among the FP and SH pattern between the two fertility levels. In 2013-2014 growing season, the UPE of each pattern in high fertility level increased significantly in contrast to the low fertility level. The lowest UTE was observed in the SH pattern among the two fertility levels. In low fertility level, The UTE of the HH pattern was lower than that of the FP pattern. In high fertility level, The UTE of the HH pattern has no significant difference with that of the FP pattern. The UTE of the three patterns in high fertility decreased significantly compared with that in low fertility level.The UPE could be calculated based on the ratio of the above ground nitrogen uptake(AGN) to the N available in soil(N ava). The SH pattern had the highest AGN at maturity among different fertility levels, but the highest nitrogen fertilizer rate lead to the highest N ava which is the main reason to its lowest UPE. The HH pattern’s AGN was lower than the SH pattern but higher than the FP pattern which along with the low N ava lead to the highest UPE.The UTE was positively related to the nitrogen harvest index(NHI) and negatively related to the grain nitrogen concentration(GNC). The NHI of the SH patterns was lowest among the three patterns in different fertility levels. The NHI of the HH pattern was equal to that of the FP pattern in low fertility level. The NHI of the HH pattern was higher than that of the FP pattern in high fertility level. The NHI of each pattern in low increased significantly compared with that in high fertility level. The GNC of the SH patterns was highest among the three patterns in different fertility levels. Equal GNCs were obtained among the HH pattern and the FP pattern. 3 The effect of different cultivation patterns on nitrogen accumulation, nitrogen transloc ation and nitrogen distribution.The effect of different cultivation patterns on nitrogen accumulation dynamics was significant. In low fertility level, the AGN of SH was higher than that of HH and FP pattern at wintering, booting, anthesis and maturity significantly. The AGN of the FP pattern was higher than the SH and HH pattern at jointing, But its AGN was lower than that of the HH pattern due to its lower nitrogen accumulation post-anthesis. In high fertility level, the AGN of SH was higher than HH and FP at booting, anthesis and maturity significantly. The AGN of the FP pattern was higher than the SH and HH pattern at wintering and jointing. The HH pattern had the highest nitrogen accumulation rate among period of booting to anthesis and anthesis to maturity which lead to its higher AGN at maturity than that of the FP pattern.In present study,the redistribution efficiency of nitrogen accumulated pre-anthesis(RENP) in leaf of the FP pattern increased significantly, the nitrogen amount accumulated postanthesis(NAP) and the contribution of NAP to grain nitrogen(CRNP) decreased significantly in contrast to the SH and HH patterns.Compared with the SH pattern, the redistribution amount of nitrogen accumulated pre-anthesis(RANP) of the HH pattern decreased significantly with the increase of RENP and RENP in stem and sheath. Equal RENP was observed among the SH and HH pattern.The distribution of nitrogen in wheat plant was affected by cultivation pattern significantly. The nitrogen distribution amount(DA)in vegetative organs of the SH pattern was higher than that of the HH pattern at anthesis significantly. In the 2013-2014 growing season, the DA in stem and sheath of the HH pattern in high fertility level were equal to that of the FP pattern, the DA in the other vegetative organs of HH decreased significantly compared with the FP pattern. At maturity, the DA in grain of the SH was higher than those of the other two patterns, but its distribution proportion(DP) in grain was lowest among all cultivation patterns. There is higher DP of nitrogen in vegetative organs at maturity.