Study Of Polyacrylamide Super Absorbent Polymer And Seaweed Fertilizer Combined Application On Apple Production

This experiment has been conducted during 2014~2015 at Zhongzhuang town,Yiyuan.Twenty-year-old ‘Fuji 3/malus robusta’ apple trees were used.On the base of traditional fertilizing scheme adopted by local orchard owner in autumn(CK:apply seaweed fertilizer 40 kg per tree),we designed the combination of polyacrylamide super absorbent polymer(PAM)levels(80g per tree,120 g per tree,160 g per tree)and seaweed fertilizer levels(24kg per tree,40 kg per tree,56 kg per tree)to explore the effects of PAM levels and seaweed fertilizer levels on soil nutrient,tree growth,fruit yield and fruit quality,and to screen the most appropriate scheme of PAM level and seaweed fertilizer level for optimizing the traditional scheme.The main results were as follows:1.The soil nutrition condition could be improved by proper combining of PAM and seaweed fertilizer.Applying PAM can make the water content and the available N content in soil higher than CK and the best level of PAM is 120 g per tree.With the increase of seaweed fertilizer consumption,the soil water increases at first and decreases then,and the content of available N,the content of available P and the content of available K in soil increase to some degrees.Compared to the CK,combined application of 120 g PAM and 24 kg seaweed fertilizer per tree(P2S1)was the optimal combination,followed by combined application of 80 g PAM and 24 kg seaweed fertilizer per tree(P1S1),which led the soil water content and the content of available N increase significantly,the total salt content decrease significantly and the content of available P,the content available K and the content of organic matter have no significant change.2.The growth of apple trees could be improved by proper combining of PAM and seaweed fertilizer.The use of PAM could promote the vegetative growth(The new shots length,the leave area and the Weight of 100 leaves increase.)of apple trees,and let the content of N in leave increased by 4.66%~30.17%,the content of P in leave increased by 10.32%~18.86% and the K in leave increased by 30.81%~37.59%,but had no obvious effect on the values of Pn and Fv/Fm.With the increased of seaweed fertilizer consumption,the vegetative growth of appletrees became weakened,the content of N in leave increased after decreased first,the content of P in leave increased relatively,the change trend of content of K in leave was not obvious and the values of Pn and Fv/Fm decreased.Among the three levels of PAM,120 g per tree was the best for the vegetative growth of apple trees.Among the three levels of seaweed fertilizer,24 kg per tree,was better significantly than CK for the vegetative growth of apple trees,which means the P2S1 is the optimal combination for the vegetative growth of apple trees.3.Fruits’ yield quality could be promoted by proper combining of PAM and seaweed fertilizer.Applying PAM for soil can increase the yield by 1.93%~27.79% compared with CK.Under the same level of seaweed fertilizer,with the increase of dosage of PAM,the yield of per tree is flat after increase first.Under the same level of PAM,with the increase of dosage of seaweed fertilizer,the yield of per tree continued decline.Compared to CK,applying PAM could raise the yield of per tree by 10.93%~36.99% when reduced the dosage of seaweed fertilizer from 40 kg per tree to 24 kg per tree,and the P2S1 has the best effect of yield promotion.Supplying PAM of 80 g or 120 g per tree to soil could significantly increase the single fruit weight,the Vc content and the ratio of sugar-acid of fruit and reduced the hardness of fruit and the content of acid of fruit obviously.Supplying PAM of 160 g per tree instead of120 g per tree for soil could not promote the above-indicators of quality obviously,and reduced the fruit shape index,the hardness of fruit,the content of soluble solid and soluble sugar in fruit instead.To increase the dosage of seaweed fertilizer can increase the hardness of fruit,but led the weight of signal fruit,the value of sugar-acid ratio and the content of soluble solid,vitamin C and acid reduced at the same time.The content of aroma matter of fruits of combinations of P1S1,P2S1 was more than that of CK.Under the same level of PAM,the content of aroma matter reduces with the increase of the dosage of seaweed fertilizer,and it was least when the level of PAM was 160 g per tree.When the dosage of seaweed fertilizer was 24 kg per tree,the content of aroma matter of fruit decreases with the increase of PAM.When the dosage of seaweed fertilizer was 40 kg per tree or 56 kg per tree,the content of aroma matter of fruit increased first and then decreased with the increase of PAM and the P1S1 had the highest content of aroma matter followed by the P2S1.The principal component analysis on the aroma matters showed that both the dosage of PAM is 80 g per tree or 120 g per tree and the dosage of seaweed fertilizer was 24 kg per tree could promote the aroma quality of fruit,and both the dosage of PAM was 160 g per tree andthe dosage of seaweed fertilizer was 40 kg per tree or 56 kg per tree were not good to the aroma quality of fruit.In conclusion,under the experimental condition the combination of PAM and seaweed fertilizer which had the best application effects in apple production was the P2S1 followed by the P1S1.