The Pattern Of Characteristice Of Nutrients Requirement And Balanced Fertilization On The Mainly Recommended Jujube Varieties In Northern Shaanxi

In this study, the mainly recommended jujube varieties in northern Shaanxi“QiYuexian”,“JingZao60”and MuZao were taken as trial materials. Through the3414field trial, the pattern of requirement of fertilizer field trial and laboratory analysis, it wasconducted to study the effects of different proportions of fertilization on yield and quality,biomass variation and NPK uptake and accumulation rule of jujube. Based on these results,scientific basis in Northern Shaanxi was provided to fertilize scientifically and legitimately,improve fertilizer use efficiency and increase farmers’ income.The main results were asfollows:(1)The3414fertilizer trials results showed that the combined application of NPK datescould significantly improve the yield which was better than the effect of single fertilizerapplication. Of all the treatments, treatment N2P2K2(N: P2O5: K2O1.92:1:1.67) was the best,which increased the field by about51%and the economic efficiency by40,000yuan/hm2ormore for two years. Deficiency analysis found that soil fertility was moderate at theexperiment field and the effect of fertilizer was K> N> P. The univariate regression analysisshowed that it was a parabolic relationship between the yield and NPK. With the increase ofNPK, the yield increased firstly and then decreased. The dualistic regression analysis showedthat the effect of NP on the field was not significant, while the PK interaction was strong.Reasonable ratio of NPK fertilizer could increase the fruit weight of jujube, reduce acidity,increase the amount of sugar and sugar acid ratio, increase vitamin C and improve jujubefruit quality. It was likely to cause quality degradation with no fertilizer or single fertilization.(2) The results of the pattern of requirement of fertilizer field trial showed that the drymatter quantity changed consistently. After flowering, the dry matter quantity increasedsignificantly. In florescence and fruit expanding process the rate was fast. In the growthperiod, the NPK content of the two jujube changed consistently. Overall the NPK content ofroots, stems and leaves decreased.The NPK accumulation of the two varieties dates was different. MuZao was in thesapling stage, of which the NPK accumulation gradually increased with advancing growth period. In the fruit maturation period fruits’ accumulation maximum was N6.22g/plant,P0.72g/plant, K6.64g/plant. Nitrogen accumulation of JingZao60increased by leaps andbounds in two stages: one was from germination stage to florescence, the other one was fromfruit expanding process to fruit maturation period. In the fruit maturation period fruits’accumulation maximum was N4.74g/plant, P0.56g/plant, K6.64g/plant. MuZao and JingZao60in each period nitrogen (N) phosphorus (P) and potassium (K) uptake and accumulationratio was germination stage11.8∶1∶8.3,3.5∶1∶3.2; florescence48.3∶1∶33.3,12.0∶1∶20; fruit expanding process9.6∶1∶20.0,1.8∶1∶3.8; fruit maturation period7.7∶1∶5.9，12.9∶1∶5.0. NPK accumulation order was K> N> P.In1000kg jujube fruit nitrogen, phosphorus and potassium which MuZao needed toabsorb were20.7kg,2.39kg,22.10kg, while JingZao60needed to absord19.64kg,2.31kg,23.66kg. When the target yield of MuZao was15t/hm2, recommended fertilizer amount wasN173.58kg/hm2, P2O592.83kg/hm2, K2O164.30kg/hm2(the ratio was1.87:1:1.77). Whenthe target yield of JingZao60was15t/hm2, recommended fertilizer amount was N173.9kg/hm2, P2O5101.1kg/hm2, K2O,163.2kg/hm2(the ratio was1.72:1:1.61).(3)Results of leaf mineral elements variation trial showed that the dry matter quantity ofleaves gradually increased with the growth of plants from0.08kg/plant in germination stage to0.52kg/plant in fruit maturation period. From germination stage to florescence was the mainstage of dry matter accumulation. And then the accumulation rapid slowed.In the growth period, the NPK content was gradually decreased and the order was N>K> P. Ca content increased quickly from8.5g/kg to15.0g/kg while Mg, Cu, Zn contentdecreased. Fe, Co and Mo content increased to florescence and then began to decrease. Mnincreased firstly and then decreased. Among N, P, Cu, Zn and Mg, positive correlation wassignificant while between Ca and them negative correlation was significant. Jujube liked Caand Fe. It could be sprayed N, P, K, Ca, Mg and Zn before germination stage. Appropriateperiod was June for NPK.