COMBINED APPLICATION OF OIL PALM BUNCH ASH AND NPKMg EFFECT ON SOIL, PLANT NUTRIENTS AND GROWTH OF OIL PALM SEEDLINGS

Abstract

Because of scarcity and cost of NPKMg fertilizer recommended for oil palm production, there is need to study effect of wastes generated during processing of oil palm fruits into oil. The oil palm bunch ash (OPBA) is generated as a result of burning empty fruit bunch during cooking of oilpalm fruits to produce oil. This work is a study of effect of OPBA, NPKMg used alone or combined at different rates on soil chemical properties, nutrient composition and growth of oilpalm seedlings. A field experiment was conducted at two locations namely; (Nigerian Institute for Oilpalm Research, Benin City) and Okpare in Delta State of Nigeria to study the effect of oil palm bunch ash (OPBA) used alone and combined with NPKMg fertilizer on soil and plant nutrients composition and growth of oil palm. The nine treatments replicated three times on oil palm seedlings were control, 0g OPBA + 125g NPKMg, 0g OPBA + 250g NPKMg, 60g OPBA + 0g NPKMg, 60g OPBA + 125g NPKMg, 60g OPBA + 250g NPKMg, 120g OPBA + 0g NPKMg, 120g OPBA + 125g NPKMg,120g OPBA + 250g NPKMg per seedling. Composite soil sample were collected at 0 – 15cm depth at Nifor and Okpare sites. Soil samples collected for the treatments were chemically analyzed. Nutrient analysis was done for plant samples. Growth parameters determined monthly from 1 to 5 months after treatment application. The test soils were loamy sand and were slightly acidic, low in organic matter (OM), N, available P, exchangeable Mg and Ca. The OPBA, NPKMg and their combinations increased soil N, P, K, Ca, Mg, pH and plant N, P, K, Ca and Mg. Generally, the treatments increased stem girth, plant height, number of leaves and leaf area relative to control. The 60 g OPBA + 250 g NPKMg and 120 g OPBA + 125 g NPKMg had highest values of nutrients. Both OPBA and NPKMg stimulated availability and combination of 60g OPBA + 250g NPKMg, 120g OPBA + 125g NPKMg, 120g OPBA + 250g NPKMg and sole 250g NPKMg gave significantly higher leaf production. The combinations are recommended.