Evaluation Releasing Efficiency of Selected Micronutrients from Natural Polymer Complex in Laboratory and Field Conditions

Abstract

This work is a part of long program for producing natural polymers which is used for application in different purposes in agriculture fields. A part of this program was the preparation of various compositions of Gum Arabic (GA) and Poly vinyl alcohol (PVA) with studying its physical and chemical characters. Whereas, the present work was concerning with the evaluation of released amount of selected micronutrients from the same complex under laboratory and field conditions.

In the laboratory, the prepared complex containing copper (Cu) or manganese (Mn) separately, were tested at different pH values for releasing at intervals.

The obtained results showed the possibility of using the Mn⁺² complex at 3000 mg kg⁻¹. Moreover, the obtained results showed that the maximum released amount was obtained at pH 7.0. A field experiment was planed according to the resulted data obtained in laboratory.

Samples were taken for elemental analysis either from soil or plants during all growth stages likeas vegetative, flowering, bear pods, full pods and harvesting. This analysis involved some selected macro- and micro nutrients such as N, P, K, Fe and Mn either in soil or plants (straw and seed). These results proved that efficiency of Mn-complex can release 1.0 and 34.0% to soil, and plants from used complex, respectively. Some increase in most of other elements compared with untreated plants was also obtained. The presence of the absorbed Mn⁺² from this complex activate the growth of plants and consequently increased the yield of seed than untreated samples. There is a linear relationship between the amount of absorbed Mn⁺² and the growth stages of the plants. This linear relationship has significant correlation coefficient (R ² = 0.5) of Mn⁺² uptake by straw or seed plants after end of stages.

Notes

*Conc. of Mn, Fe are 0.6 and 1.24 mg kg⁻¹ in soil, respectively.

*Difference = {(Complex–Control)–Mn content of the soil}.

• (%) = Difference values/3000 (mg kg⁻¹) × 100.

Mn content of the soil = 0.6 mg kg⁻¹.

• Standard Deviation (±SD); average of three samples.

• Sd±three values per each

1- Vegetative stage (35 days of planting). 2-flowering stage (50 days of planting).

3-Bear pods stage (75 days of planting). 4-Full pods stage (90 days of planting).