Reducing Mineral Fertilizers by Using Organic Manure to Improve Washington Navel Orange Productivity and Sandy Soil Characteristics

Document Type : Original Article

Authors

1 Pomology Dept., Fac. of Agric. (El-Shatby), Alex. Univ., Egypt.

2 2Citriculture Dept., Hort. Res., Inst., Agric. Res. Center

3 Soil, Water and Environment Res., Inst., Agric. Res. Center

Abstract

A field experiment was conducted during 2007/ 2008 and 2008/ 2009 seasons in a private orchard at El- Boustan region, EL-Behera Governorate, on 15 year old Washington navel orange trees (Citrus sinensis, L.)
budded on sour orange rootstock (Citrus aurantium, L.).
Trees were fertilized with mineral and organic fertilizers alone or in combinations. The used mineral fertilizer (T1) was 4.76 kg /tree ammonium sulphate added in three equal doses in March, May and August, 1.19 kg /tree potassium sulphate added in March and August in two equal doses and, 1.49 kg /tree calcium super phosphate added in March of both seasons. Moreover, the used organic manure (O.M) composed of 27.7 kg/ tree compost equal to 900 g N, 200g P2O and 500g K2O) added in November of both seasons. Results indicated an improvement in physical and chemical properties of the fruits by treatments including organic manure and mineral fertilizer. Moreover, the treatment (T6) 80% M.F +20% O.M significantly resulted in the highest values of fruit set, fruit retention, yield, TSS, acidity and vitamin C content. In addition, all treatments which contain organic manure significantly increased leaf mineral contents.Application of
organic manure alone or in combinations to sandy soil improved its physical and chemical properties which
reflected on soil fertility and structure. This improvement in soil structure, which reflected on increasing values of cation exchange capacity(CEC), available water (A.W), field capacity (F.C), total porosity %(T- porosity), soil organic matter (S.O.M),and decreasing of bulk density (fB). In the same time, such increase was more pronounced in content of plant nutrients (NPK) which was obtained by applying 40% M.F + 60% O.M (T4).

Main Subjects