| Yuanmou is an important hometown of vegetables and fruits in Yunnan Province,and the red pitaya（Hylocereus polyrhizus）has considerable economic value and has been widely planted in this area in recent years.However,the application of a large number of chemical fertilizers has caused problems such as soil acidification,compaction,low fertility,and nutrient imbalance,which restrict the sustainable development of the local economy and ecological environment.Therefore,how to find the best fertilization method according to local conditions,improve soil fertility,and improve the soil environment at the same time,has become a key issue that needs to be solved urgently in the sustainable use of the soil in the pitaya orchard.Therefore,this article has conducted field trials for three years（2018～2020）,with CK as the control,and adopted a 3×3 complete scheme design to explore the three ratios of biochar addition（by carbon fertilizer ratio at 0%,3%,and6%,namely B0,B3,and B6）and the three levels of organic fertilizer application(low-22.5,medium-45,and high-90 t·hm-2,namely L,M and H)under the influence of soil fertility,yield and quality.The evaluation method provides a reference basis for the application of the combined application of biochar and organic fertilizer to improve the quality and yield of red pitaya.The main conclusions of this study are as follows:（1）Research on the effect of combined application of biochar and organic fertilizer on soil water retention shows that compared with CK,combined application of biochar and organic fertilizer can increase the soil natural moisture content,soil saturated water holding capacity,soil capillary moisture capacity and soil field capacity of 0-20 cm and 20-40 cm soil layers in three years.Among them,the soil natural moisture content of the 0-20 cm soil layer under the B3M treatment was higher than other treatments in the three years.Except for CK,there was no significant difference in the soil natural moisture content of the 20-40 cm soil layer between the treatments（P>0.05）.The combined application of 3%biochar and organic fertilizer has a better overall improvement effect on the soil saturated water holding capacity,soil capillary moisture capacity and soil field capacity of 0-20 cm soil layer.However,the combined application of 6%biochar and high amount of organic fertilizer will be effective in 2020.Annually,the saturated soil saturated water holding capacity and field capacity of 20-40 cm soil layer have been increased.（2）The research by measuring the physical and chemical properties of the soil shows that the combined application of biochar and organic fertilizer reduces the soil bulk density compared with CK,increases the soil total porosity,p H,organic matter,total and available nutrient contents,and improves the soil layer of 0-20 cm than20～40 cm.Among them,there was no significant difference in bulk density and p H between the treatments in 2018（P>0.05）.Compared with CK treatment,the soil bulk density of 0-20 cm and 20-40 cm soil layers was reduced by 6.00%～27.21%and 6.01%～23.32%in 2019,a decrease of 17.06%～29.18%and 9.07%～31.45%in2020,respectively.Compared with CK,soil p H of 0-20 cm and 20-40 cm soil layers increased by 0.08-0.26 and 0.16-0.30 units in 2019 and 2020.The soil organic matter content of 0-20 cm and 20-40 cm soil layers increased by 30.00%and 60.00%,64.21%and 67.38%,95.43%and 80.61%in 2018,2019 and 2020.Application of high amount organic fertilizer or combined application with biochar can significantly increase the total nitrogen,available nitrogen and available potassium content of the soil.The content of total phosphorus,available phosphorus and total potassium in the soil layer of 0-20 cm soil in 3 years under the treatment with 3%or 6%biochar was higher.（3）Research on the response of pitaya yield and quality to the combined application of biochar and organic fertilizer showed that high amount organic fertilizer application or combined application with biochar and low or medium amount organic fertilizer is more conducive to quality and high yield.Among them,application of organic fertilizer increased the yield and Vc content of red pitaya in2018.Adding 3%or 6%biochar combined with low and medium organic fertilizers can improve the yield and quality of red pitaya.With the passage of time,the advantages of using biochar have gradually increased.The Vc,reducing sugar and soluble protein content of red pitaya have also increased relatively,and the soluble solid content of the three years under the B6L treatment is the highest.（4）The analysis of economic benefits showed that the economic benefits of red piyaya under the treatment of B6L and B3M were higher in three years.The increase in the amount of high amount of biochar and organic fertilizer increased the input cost and resulted in negative income.（5）Eight soil fertility indexes were selected for soil quality evaluation,and the results showed that the total nitrogen,total phosphorus,total potassium,available phosphorus and available potassium content in soil can reflect 87.39%of the original information,and soil property indicators through factor analysis.There is a significant or extremely significant correlation between the soil fertility.The comprehensive scores of soil quality are treated with B6L and B3M,which is consistent with the results of economic yield analysis.In summary,adding 6%biochar and low amount of organic fertilizer(22.5t·hm-2)or adding 3%biochar and medium amount of organic fertilizer(45 t·hm-2)is more effective and could achieve the purpose of improving quality and high yield. |
PDF Full Text Request