Response of a newly reclaimed calcareous soil at the eastern rim of el fayoum depression to agrochemical amendment for sustaining its agricultural utilization

الملخص EN

Agricultural utilization of desert marginal soils at El Fayoum Governorate edges is of importance to support the local farmer incomes, particularly under the best and suitable management practices of land and available water resources.

The choice a newly reclaimed soil encompassing by Eocene limestone at the eastern edge of Tamia district was a matter of concern in this work.

It is a sandy clay loam in texture, slightly saline, non-sodic, and calcareous in nature with a subsurface diagnostic horizon of calcigypsic one, and classified as Typic Calcigypsids, fine loamy, mixed, hyperthermia, moderately deep.

According to a parametric system, it could be evaluated as moderately suitable (S2ws3s4), with soil limitations of wetness, soil depth and CaCO3 content, with an intensity degree for each lies in the range of slight-moderate (rating = 90-80).

The obtained analytical data pointed to a considerable decrease in soil productivity due to high CaCO3 content and low organic matter content as well as a relatively high soil pH value.

These factors are the main reasons of deficiency for most plant nutritive elements, particularly phosphorus and zinc in the soil under study.

Hence, suitable agrochemical amendments have to be applied to sustain its productivity and to minimize the possible adverse effects of both high CaCO3 content and soil pH.

Therefore, a field experiment was conducted on the chosen soil, where lentil plants (Lens esculenta c.

v.

Giza 9) were sown during the winter season of 2005-2006.

The investigated soil plots were irrigated with the available irrigation water source (mixture of the Nile and drainage waters at a ratio of 1 : 1) in a randomized complete blocks design with three replicates.

The agricultural management practices were conducted as usual, where elemental sculpture was applied to the soil plots (i.

e., agrochemical soil amendment) at four rates (i.

e., 0, 250, 500 and 750 kg S fed-1), while Zn was foliar sprayed on the grown plants (i.

e., supporting Zn deficient) at three rates (i.

e., 0, 450 and 900 g fed-1).

The results showed that applied S and Zn, especially at their highest rates together, caused more pronounced increases in the vegetative growth parameters, i.e., number of bacterial nodules / plant, dry weight of bacterial nodules / plant, plant height, number of branches / plant and number of pods / plant.

The corresponding relative increases at the highest applied rates of S and Zn (750 kg S / fed + 900 g Zn / fed) were 92.61, 191.38, 34.27, 69.95 and 83.58% over the control treatment, respectively.

Increase percentages in soil organic matter, N, P, K, Fe, Mn and Zn vs decrease percentage in soil pH occurred due to the dual application of (750 kg S / fed + 900 g Zn / fed) after 55 days from planting were 60.78, 65.02, 78.05, 54.14, 44.76, 51.83 and 119.74% vs-10.62% over and below the control treatment, respectively.

At harvest, seed weights/plant or /fed, 1000 seed weight and seed protein % as well as N, P, K, S and Zn uptake by seed were also positively affected, where the corresponding relative increases at the treatment of (750 kg S/fed + 900 g Zn/fed) reached 82.85, 71.59, 77.27, 42.28, 42.31, 87.88, 28.06,71.79 and 61.01 % over the control, respectively.

As a conclusion, it could be deduced that application of S as a soil amendment at a rate of 750 kg/fed in combination with any micronutrient deficient as foliar spray is important to sustain soil productivity and to obtain economically best crop yield attributes under such a soil calcareous in nature for avoiding a direct restrictive effect of CaCO3 on the nutrients released and their mobility towards plant roots.

This is true, since the suggested sulphur efficiency at the recommended S rate for lentil seeds utilization of N, P, K, S (macro) and Zn (micronutrients) was 105.47, 156.82, 88.60, 141.83 and 114.28 %, respectively.