Hydrophilic Polymers for Improving the Conditioning Effect of Manures and Organic Composts. LProduction and Water and Fertilizers Use Efficiency for Tomato grown in Sandy Soil

摘要

ATWO successive years (2004-and 2005) completely randomized field experiment with trickle irrigated tomatoes (Lycopersican esculentum, var. 448) as the indicator plant was conducted on a sandy soil at El-katta, Giza governorate to study the conditioning effect of hydrogels when mixed with or grafted on organic composts on production and water and fertilizers use efficiency by growing plants. Examined treatments were: a) untreated soil, b) soil treated with 0.5 kg and 1 kg organic compost (OM) / plantpit, c) soil treated with 2g and 4 g polyacrylamide K polyacrylate gel (G)/plant pit, d) soil treated with mixtures of 0.5 kg OM + 1g G, 0.5 kg OM + 2g G, 1kg OM +:1 g G and 1 kg OM + 2 g G /plant pit, and e) soil treated with 12.5 g and 25 g polyacrylamide K polyacrelate grafted on organic compost (grafted G)/plant pit. Produced yields by the unit of irrigation water or added fertilizers prove the importance of using either OM or G or both together for increasing the agricultural potentialities of sandy soils under the severe conditions of our deserts, i.e., the limited water resources and the inadequate water retention and low fertility of such soils. Grafting G on OM leads to the production of an effective soil conditioner. Incorporating this conditioner in sandy soil improves its productivity and both water and fertilizers use efficiency by growing plants. The conditioning effect of studied treatments could be descertdingly arranged as follows: 25g grafted G = 1kg OM +2g G > 0.5kg OM + 2g G >4g G> 1kg OM + 1g G >12.5g grafted G > 0.5kg OM + 1g G s 2g G > 1kg OM > 0.5kg OM / plant pit.