Effectiveness of Applying Natural Soil Conditioners Under Moisture Regimes on Sandy Soil Properties and Cereal Crops Production

Abstract

Two experimental sites of arable sandy soil located at Abou Omera Al-Sharkeya village , Baltim district, Kafr El-Sheikh Governorate were chosen. The selected locations represent the conditions of circumstances of northern part of Nile Delta region. Site 1 (fruit field) was devoted for collecting composite surface soil sample for carrying out wheat pot experiment in plastic pots during the growing winter season period 2010/2011. Site 2 (nearby site 1) was occupied for conducting maize field experiment during growing summer season period 2011. The main objectives of this investigation were to study and evaluate the effect of natural raw minerals, soil conditioner types, their mixtures and application rates in sandy soil subjected to different irrigation deficits on the following parameters: (i) soil properties(chemical, physical, moisture constants and nutritional status after cereal crops harvesting and (ii) agronomical production of wheat and maize crops after full maturity in the studied soil under consideration. Four types of soil conditioners [bentonite , compost , mixture of natural mineral raw materials (MNRM)and their mixtures 1:1:1(w/w)] were applied before cultivation in two recommended application rates low (R1) and high (R2). Three levels of soil moisture depletion regimes were used (30, 50 and 70 %) from its available water capacity. The N,P,K mineral fertilizers were added according to the recommended doses for sandy soils. Applying natural soil conditioner types, their mixtures and application rates in the studied sandy soil subjected to moisture depletion regime realized improving soil chemical, physical, water holding capacity and macro nutritional status. Soil salinity (soil reaction, electrical conductivity and ionic strength), hazard sodium parameters (soluble sodium percentage and sodium adsorption ratio), soil porosity, available water capacity and phytoavailable nutrients were increased. On the other hand, hydraulic conductivity and bulk density were decreased. Generally, high application rate achieved the best values of soil properties in comparison with low application rate. Conditioner mixtures 1:1:1 treatment realized the superiority under wheat pot experiment, meanwhile, compost treatment achieved the best values under maize field experiment. Irrigation after 50 % AWSMD gave moderate values of such properties between wet (30% AWSMD) and dry (70% AWSMD). Increasing grains, straw, protein, grains weight, harvest index and other yield components significantly for wheat and maize crops, as a result of adding soil conditioners compared with control. Conditioner mixtures 1:1:1 treatment realized the superiority under wheat pot experiment, meanwhile, compost treatment achieved the best values under maize field experiment. Also, high application rate was better than low application rate. Results also indicated that , from view point of water and economic , the highest values of crop yield were obtained from irrigation at 50 % depletion from its available water capacity rather than 30 % and 70 % ...