جستجوی مقالات مرتبط با کلیدواژه « تجزیه برگ » در نشریات گروه « آب و خاک »

The low solubility of nutrients in the soils of most arid regions, such as Khuzestan, limits or reduces plants growth. Application of organic sulfur to the soil reduces soil alkalinity, increases nutrient absorption and plant growth. This experiment was conducted in a randomized complete block design with split plot design. Experimental treatments consisted of three date palm offshoots weights including 5-8, 8-11, and 11-15 kg in the main plots and four organic sulfur compounds levels as 0, 400, 800, and 1200 gram per plants in sub plots with 4 replication. The study was conducted at Date Palm and Tropical Fruit Research Institute. Results of leaves analysis after performing the experiment showed that organic sulfur compounds improved soil condition around the roots and caused significant increase in leaf nutrient uptake. The highest levels of nitrogen, and potassium content were 2.025 and 2.262 percent and belonged to treatment of 1200 g. organic sulfur per plant. In addition, date palms offshoots weight treatments showed significant differences in growth. The highest rates of growth in trunk diameter and length, seedling length, leaf length, and width were, respectively, 6.7, 16.4, 80.8, 8.4, and 6.8 cm, and were observed in the heaviest offshoots. Organic sulfur treatments had significant effects on stems and leaf growth. The highest rates of growth in trunk diameter and length, seedling length, leaf length and width, were 7.7, 20.1, 85.3, 10.8 and 8.1 cm and 8.6 leaves, belonging to the highest level of organic sulfur treatments. Comparison of the interactions also showed that organic sulfur compounds application at any shoot weight increased growth rate significantly. Finally, the off shoots weight range of 11-15 kg and application of 1200 grams of organic sulfur compounds can be recommended for date palm cv. Mejool offshoots growth.

Diagnosis and recommendation integrated system (DRIS) and deviation from optimum percentage (DOP) index can be used as efficient methods to interpret the results of plant analysis and the nutritional diagnosis in crops and fruit trees. To establish DRIS norms in seedless grape (Sultana, cv) and compare them with DOP index, leaf samples were collected from 129 vineyards and analyzed for N, P, K, Ca, Mg, Fe, Mn, Zn, Cu and B concentrations. The sugar content (brix) of the grape juice was measured as a criterion of yield. On the basis of sugar content, the vineyards were divided into two groups of low and high yielding populations. Standard DRIS norms were established for the different nutrient ratios. DRIS indices were calculated to evaluate nutrients balances and order of nutrients requirements. Sufficiency ranges of macro and micro nutrients were derived by DRIS technique. Means of nutrients concentrations in the high yielding population (high sugar content) were used as reference values for calculating DOP indices. DRIS-derived sufficiency ranges were 2.0-2.8, 0.20-0.27, 1.2-1.7, 1.5-2.1% for,respectively, N, P, K, Ca, and Mg, and 55-138, 40-127, 30-100, 10-20, 30-187 mg/kg for Fe, Mn, Zn, Cu, and B, respectively. DRIS indices showed that, among the macro and micro nutrients in all low yielding vineyards, magnesium and zinc had the most negative index values, respectively. The nutritional balance index (NBI) of DRIS and of DOP (SDOP) were much more than zero in all low-yielding vineyards, indicating that there was imbalance between the absorbed nutrients by grape vines. Comparison of the DRIS indices for the macro and micro nutrients with the DOP indices revealed that Mg and Zn were the most deficient elements in all low-yielding vineyards showing that both methods provide similar information in the interpretation of the results of leaf analysis. To validate DRIS norms and verify the efficiency of DRIS and DOP as methods for improving the interpretation of analysis results of grape leaf, fertilizer experiments should be conducted on seedless grape in a low-yielding vineyard.