Nutrient Management Status And Optimal Fertilization Of Zanthoxylum Armatum V. Novemfolius In Chongqing

Zanthoxylum is one of the important industries in western areas of Gansu,Yunnan,Sichuan,Chongqing and so on,which has the characteristics of tolerance to barren,easy cultivation,easy management,high economic value,etc.In recent years,the planting area of Zanthoxylum armatum v.novemfolius has expanded rapidly,but the research on its cultivation and management techniques lags behind,and farmers generally apply fertilizer by experience.Chongqing is the fourth largest Zanthoxylum production area in China.Zanthoxylum armatum v.novemfolius is the main cultivar in Chongqing.The strong retractive pruning is adopted in the cultivation and management every year,and its demand for nutrients is different from other varieties.However,it is not clear about the growth and nutrient requirement of Zanthoxylum armatum v.novemfolius,and there is little research on fertilizer management of Zanthoxylum armatum v.novemfolius.In this paper,in Jiangjin District of Chongqing,the main producing area of Zanthoxylum armatum v.novemfolius,first of all,through household investigation and soil sampling analysis,we can understand the current situation of farmers’fertilization,soil nutrient fertility and existing problems in Zanthoxylum armatum v.novemfolius orchard.It provides the basic data for the nutrient optimization management of Zanthoxylum armatum v.novemfolius in this area.At the same time,the effects of nitrogen on yield,quality and nitrogen uptake and utilization of Zanthoxylum armatum v.novemfolius were studied by field experiments and optimized fertilization experiments.In order to provide support for scientific fertilization of Zanthoxylum armatum v.novemfolius,the rule of dry matter accumulation and nutrient absorption in different growth stages and the optimum proportion of nitrogen fertilizer and nutrient were determined.The main results are as follows.The results of investigation on farmers in 5 main towns and villages in Jiangjin district of Chongqing showed that there was a large yield difference among farmers.The yield range of Zanthoxylum armatum v.novemfolius in Chongqing was 1.63-18.7 t·hm^-2,and the average yield was 9.87 t·hm^-2.The average application rate of N,P₂O₅ and K₂O was 351,220 and 288 kg hm^-2,respectively.and the nitrogen,phosphorus and potassium fertilizer input in the organic fertilizer only accounted for 2.64%,1.75%and2.22%of the total nutrient input,respectively.The average application rate of nitrogen,phosphorus and potassium in high yield and high efficiency was 272,164 and 218kg·hm^-2,respectively,and the partial factor productivity was 42.6,75.7 and 54.7 kg·kg^-1,which was 29.1%,30.2%and 36.8%higher than the average partial factor productivity of nitrogenous,phosphorous and potassium fertilizers.The application of organic fertilizer could significantly increase the yield of Zanthoxylum armatum v.novemfolius,and compared with that without organic fertilizer,the yield increased by 17.8%,and the combination of organic and inorganic fertilizer is an important measure to increase the yield of Zanthoxylum armatum v.novemfolius.Soil nutrients data in 1189 Zanthoxylum armatum v.novemfolius orchards showed that the average contents of soil organic matter,hydrolyzed nitrogen,effective phosphorus and available potassium were 14.2 g·kg^-1,85.8 mg·kg^-1,7.6 mg·kg^-1 and119 mg·kg^-1,respectively.The lack of soil organic matter,hydrolysis nitrogen and effective phosphorus in the soil was 90.8%,64.6%and 77.3%,respectively.The available potassium in the soil is at a moderate level,and The percentage of lack is44.6%.The average pH of the soil was 6.0,Only 37.9%of the soil pH value is suitable for the growth of Zanthoxylum armatum v.novemfolius pH range of 6.5 to 8.5,and the acid soil was 62.1%.The average contents of available Cu,Zn,Fe and Mn in soil were3.05 times,2.0 times,2.1 times and 3.06 times higher than those in 2005 in 1.86mg·kg^-1,4.22 mg·kg^-1,27.8 mg·kg^-1 and 108 mg·kg^-1,respectively.Field experiments with different nitrogen application rates showed that the yield and quality of Zanthoxylum armatum v.novemfolius increased at first and then decreased with the increase of nitrogen application level,the optimum nitrogen application rate of 297 kg·hm^-2 was the highest.Compared with the conventional nitrogen application rate of 371 kg·hm^-2,the fresh yield and dry yield of seed coat increased by 7.97%and 9.40%,respectively,and it was 31.9%and 35.3%higher than that without nitrogen application,respectively.The yield components of Zanthoxylum armatum v.novemfolius were analyzed.The optimum nitrogen application increased the number of seeds per ear and 1000-grain weight of seed coat of Zanthoxylum armatum v.novemfolius,and thus increased the yield.Numb-taste components in optimum nitrogen application rate of Zanthoxylum armatum v.novemfolius was the highest,reaching 109mg·g^-1,indicating that the high quality and high yield of Zanthoxylum armatum v.novemfolius could be achieved by proper nitrogen application.The average nitrogen accumulation in Zanthoxylum armatum v.novemfolius in the mature period was 239 kg·hm^-2,The nitrogen uptake was higher in the period of new growth to boom,inflorescence to fruiting s and fruiting to maturity,which accounted for37.2%,27.4%and 26.5%of the annual nitrogen accumulation of Zanthoxylum armatum v.novemfolius,respectively.From the rate of nitrogen accumulation,the rate of nitrogen accumulation in the period of inflorescence to fruiting was the highest,followed by that in maturity,which were 2166 g·d^-1 and 1805 g·d^-1,respectively.It is indicated that the demand for available nitrogen is large for Zanthoxylum armatum v.novemfolius in the late stage of growth.The nitrogen utilization efficiency,nitrogen agronomic efficiency and fertilizer nitrogen contribution rate increased first and then decreased with the increase of nitrogen application level.There were the highest Under the optimum nitrogen application condition,which was 17.2 kg·kg^-1,4.17 kg·kg^-1 and 22.7%,respectively.The average phosphorus accumulation of Zanthoxylum armatum v.novemfolius was 26.1 kg·hm^-2.in the period of inflorescence to fruiting,which reached 13.3 kg·hm^-2,and the phosphorus accumulation in fruit reached 7.50 kg·hm^-2,accounted for 28.7%of the annual phosphorus accumulation of Zanthoxylum armatum v.novemfolius.The accumulation of phosphorus in the period of new growth to boom period was the second,reaching 10.2 kg·hm^-2.The average potassium accumulation of Zanthoxylum armatum v.novemfolius was 194 kg·hm^-2.at maturity.The accumulation of potassium in the period of new growth to boom period was the largest,reaching 71.4 kg·hm^-2.The average accumulation of potassium in branches and leaves reached 44.0 kg·hm^-2 and 27.4kg·hm^-2,respectively.The accumulation of potassium in the period of fruiting to maturity was the second,which was 69.1 kg·hm^-2.The results of field experiment with optimized fertilization showed that the yield and quality of Zanthoxylum armatum v.novemfolius were not significantly decreased under potassium reduction treatment.The amount of potassium fertilizer could be reduced according to the soil available potassium content.P-increasing treatment had no obvious effect on the yield of Zanthoxylum armatum v.novemfolius,but the quality decreased obviously.The seed coat yield and quality of Zanthoxylum armatum v.novemfolius.were significantly improved by adding boron and zinc,and the seed coat yield and numb-taste components were 3072 kg·hm^-2 and 101 mg·g^-1,respectively.In terms of yield components,boron and zinc application mainly increased the number of grains per ear and 1000 kernel weight of Zanthoxylum armatum v.novemfolius,and thus increased the seed coat yield.The application of organic fertilizer mainly increased the1000-grain weight of Zanthoxylum armatum v.novemfolius,increased the yield of Zanthoxylum armatum v.novemfolius.In conclusion,there was a large yield difference of Zanthoxylum armatum v.novemfolius among farmers in Chongqing.The soil nutrient status of Zanthoxylum armatum v.novemfolius orchard varies greatly,and the soil organic matter,hydrolyzed nitrogen and available phosphorus were relatively deficient,the trend of soil acidification was obvious.When nitrogen application rate was 297 kg·hm^-2,the yield of Zanthoxylum armatum v.novemfolius was the highest and the content of the numb-taste components was the highest.The yield of Zanthoxylum armatum v.novemfolius was significantly increased by adding boron,zinc and organic fertilizer,the application of potassium fertilizer could be reduced appropriately according to the soil available potassium content.The storage nutrition of Zanthoxylum armatum v.novemfolius remains to be further studied.