Soil science
Akbar Gandomkar; Zahra Khanmohammadi; M. Basirat
Abstract
Introduction
Quince with the scientific name "Cydonia oblonga Mill." is one of the most important horticultural products in the word including Iran. According to the average production from 1994 to 2020, Iran was the fourth largest quince producer in the world. Isfahan province is one of the most important ...
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Introduction
Quince with the scientific name "Cydonia oblonga Mill." is one of the most important horticultural products in the word including Iran. According to the average production from 1994 to 2020, Iran was the fourth largest quince producer in the world. Isfahan province is one of the most important centers of high quality quince production with 2432 hectares of cultivated area and annual production of 25986 tons. Most of the quince orchards are located in the cities of Natanz and Isfahan. Plant nutrition as an important factor in growth, is a function of nutrients and environmental conditions interactions. Assessing the nutritional status of plants is based on precise determination of nutrients and appropriate application method to diagnosis and interpret the results. Various methods have been used to evaluate the nutritional status of the plant, such as the Critical Value Approach (CVA), the Deviation from Optimum Percentage (DOP), the Diagnosis and Recommendation Integrated System (DRIS) and the Compositional Nutrient Diagnosis (CND). The CND method expresses interactions by considering the ratio of one element to the geometric mean of all elements. Then high and low functional groups are separated, by using mathematical and statistical methods and application of cumulative function of the variance ratio of nutrients and the chi-square distribution function. Finally, CND nutrients norms and indices such balance index are calculated step by step. Therefore, considering the importance of the quince production in the country and the lack of sufficient knowledge to determine its nutritional status, the present study was conducted with the aim of investigating the nutritional status of quince trees using the CND method and determining the nutrients norms for this product.
Materials and Methods
In order to evaluate the nutritional status of quince trees using the CND method, 28 orchards were selected in the cities of Isfahan and Natanz. The orchards were selected such a way that they had different ranges of yield. The geographical location was recorded for each orchard. Then random and composite sampling of leaves was done from branches without fruit in July 2018. Concentration of nitrogen phosphorous, potassium, calcium, magnesium, iron, manganese, zinc, copper and boron was measured in quince leaves. At the end of season, the yield was determined for each orchard. The orchards divided into two groups based on high and low yields. The CND norms, CND nutritional index and nutritional balance index (r2) were computed based on steps of Parent and Dafir. The balance index of nutritional elements (r2) was calculated by Keith-Nilson method based on the Chi-square statistical distribution function (K2) in Excel software.
Results and Discussion
According to results of cumulative distribution function of nutrient variance and considering the yield of 23 tons per hectare as the intermediate yield, 25% of the studied orchards were in the high yield group and 75% of the orchards were in the low yield group. After solving the third– rank cumulative function equations of the studied nutrients, the highest yield was obtained for potassium Fci (VK) = 21.98 and the lowest value was for nitrogen Fci (VN) = 15.37. CND standard norms of nutrients and residual value were described as: V*N= 2.91, V*P= 1.39, V*K= 2.91, V*Ca= 2.13, V*Mg= 1.35, V*Fe= -2.01, V*Mn= -3.12, V*Zn= -3.97, V*Cu= -4.85, V*B= -3.51 and V*Rd= 6.78. The CND nutrient index revealed that potassium and nitrogen had the most negative index among macronutrients in the low-yield orchard group. The low amount of soil organic matter and the high presence of sand can contribute to the negative nitrogen index. Among the micronutrients, the iron index was negative in 67.7% of the low-yield orchards. Zinc and copper had the next highest nutritional requirements in most orchards. The presence of calcareous conditions in the soil of the studied orchards may be one of the reasons for this observation. The estimation of the nutritional balance index indicated that the r2 value in orchards with low yield was 60.3% higher than that in high-yield orchards.
Conclusion
CND nutritional balance index (r2), specially in orchards with low yield was more than zero (20.85), indicating nutritional imbalance in these orchards. Proper management and balanced application of chemical fertilizers should be considered. This can increase the yield and quality of quince production.
Majid Basirat; Hassan Haghighatnia; Seyed Majid Mousavi
Abstract
Introduction: Fertilizer recommendation in orchards based on soil testing is not accurate because findings showed that there is not significant correlation between nutrients concentration in the soil and plant. Therefore, studying the nutritional status in orchards is usually based on the plant testing. ...
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Introduction: Fertilizer recommendation in orchards based on soil testing is not accurate because findings showed that there is not significant correlation between nutrients concentration in the soil and plant. Therefore, studying the nutritional status in orchards is usually based on the plant testing. In order to evaluate the nutritional status ofplants, different methods, such as Compositional Nutrients Diagnosis (CND), Diagnosis and Recommendation Integrated System (DRIS), Deviation from Optimum Percentage (DOP), Critical Value Approach (CVA) and Sufficiency Range Approach (SRA) were used. In the CND method, a determination coefficient measured which is considered as the relative superiority of this method to the others. Generally, through the CND method, a correct perception on nutritional status of plantsmay be obtained.
Materials and Methods: The nutritional status of orange orchards, Valencia cultivar, in south of Fars province (Darab town) was studiedusing the compositional nutrient diagnosis and multivariate statistical analysis methods. For this, 80 orange orchards, Valencia cultivar were selected and 30 trees in each orchard were signed. Plant samples were taken from the selected trees in the proper session and concentration of N, P, K, Ca, Mg, Mn, Zn, Fe, Cu and B weremeasured using the standard methods. Then the average yield was measured atharvest. Based on the CND method, total concentration of the nutrients in the plant was considered as a variable (Sd) plus a residual portion (Rd) that "d" is defined as the number of nutrients in the equation and Rd is defined as the residual value. Which sum of the equation equals 100 and it is based on percent. The residual/un measured nutrients and estimated by using the equation of " Rd = 100- (N+P+K+…)". Thereafter, by using the standard equations, which they were perfectly explained and presented in the material and methods section, the geometric mean of nutrients, nutrients index, nutrient balance index, and average yield and finally the reference norms were determined. In addition to the CND method, by using the Multivariate Statistical Analysis and PrincipalComponent Analysis methods, the effective and important nutrients in the yield were determined and also, ability of the CND method was evaluated. The SPSS software was used for variance analysis the data.
Compositional nutrient diagnosis (CND) analysis and multivariate analysis methods are used to study the nutritional diagnosis of Valencia orange orchards in south of Fars province. 80 valencia orange orchards were selected in the region and in each of them, 30 uniform trees were marked and sampled were taken in proper time and referenced method. Leaf elemental compositions and mean yield also were measured from selected trees for each orchard. Data analysis divided all orchards into two low and high yield groups.
Results and Discussion: The results showed that 11 orchards were as high yielding group and 69 orchards were as low yielding group and the average of optimum yields, 113 Kg tree-1, was determined as the yield goal. By using the average of measured nutrients norms for the high yielding community the concentration of the 10 studied elements was obtained which comprised: N 3.00± 0.18; P 0.17± 0.01; K 1.37± 0.12; Ca 3.32± 0.78; Mg 0.36±0.07; Mn 23± 3.35; Zn 17.3± 2.3; Fe 75± 7.3; Cu 7.81± 1.44; B 76± 19.4. Through comparison with the obtained reference norms of optimum yielding orchards, more than 50% of the studied orchards had lower N, Ca and Mn content than the obtained norm and B concentration in the high yielding group was more than 50% less than the low yielding group. Generally, the results of Multivariate Statistical Analysis and PrincipalComponent Analysis showed that N, Ca, Fe and Zn had the highest effect in changes of yield.
Conclusion: Resultsof this work showed that 13% of the studied orchards were in the high yielding group and 86% of themwere in thelow yielding group which shows the imbalance nutritional condition in the studied region. The positive effect of N and Ca on the yield may be due to the dilution effect which these nutrients can reduce the B toxicity. Abundance of Mn deficiency in the studied orchards may be due to the high concentration of Zn and Fe in the plants and antagonistic relations may be considered as the main reason. Multivariate statistical analysis methods may be used as an important tool to study the nutritional conditions of plants. Dominant percentage of the studied orchards showed low yield which may be due to the B toxicity which probably N and Ca application may be alleviated the negative effect of this element.