Abstract: Combined use of crop and animal wastes is necessary in order to obtain adequate amount of organic manure fro use in crop production. Hence field experiments were conducted at two sites in Akure, Southwest Nigeria to compare effect of NPK (15-15) fertilizer (200 kg ha-1) and each of Spent Grain (SG) and ground Cocoa Husk (CH) amended with Cattle Dung (CD), Poultry Manure (PM) and Goat Manure (GM) at equal rates (12.5 :12.5 t ha-1). The effects of treatments on leaf N, P and K concentrations growth and fruit yield of tomato were studied. Compared with control, NPKF and animal manure amended SG and CH increased leaf N and K, plant height, number of branches, leaf area, number and weight of fruits significantly (p>0.05). Fruit yields given by CD, PM and GM amended CH and M and GM amended SG were similar. Among eight treatments compared, CH and SG amended with PM gave height fruit yield, compared with control, NPKF, amended SG and CH increased fruit yield by 268, 342 and 397%, respectively.
INTRODUCTION
Nigeria tomato (Lycopersicon esculentun) production is about 600000 tonnes annually. Among the factors that contribute to its low yield is low soil fertility and inadequate use of chemical fertilizers. The cost of fertilizer is high for the farmers and fertilizer is often scarce. Hence research attention shifted to the use of agricultural wastes for supplying nutrients to tomato and other crops. These wastes such as cocoa pod husk, wood ash, oil palm bunch refuse brewery waste (spent grain), droppings of poultry, cattle and goat (MoyinJesu and Atoyosoye, 2002; Adediran et al., 2003) posed disposal and environmental problem. However recent studies have shown that they are effective as manure for enhancing yield and nutrient status of vegetables and grain crops (Adediran et al., 2003; Ikpe and Powell, 2003, MoyinJesu, 2003). Ikpe and Powell (2003) observed that about 75% of farmers in the forest zone of West Africa keep livestock predominantly goats and poultry.
Because the quantities of the agricultural wastes available may not be sufficient for large scale vegetable production (Adediran et al., 2003), there is need to combine annual and plant wastes. Studies are rare on integrated application of plant and animal manures. Ojeniyi and Adejobi (2002) found that wood ash and goat manure complemented each other as to their effects on nutrient content, growth and yield of amaranthus. Addition of 2 t ha-1 ash to 8 t ha-1 goat manure increased leaf yield of amaranthus by 54%. This research investigates effect of animal manure amended spent grain (sorghum brewery waste) and ground cocoa husk on nutrient status, growth and yield of tomato in Southwest Nigeria. The hypothesis is that the annual manure could enhance release of nutrients from the crop wastes thereby bust yield of tomato as NPK fertilizer. The aim of study is to reduce expenditure on chemical fertilizer.
MATERIALS AND METHODS
Field Experiments
Experiments were carried out at Federal University of Technology, (FUTA)
and Federal College of Agriculture (FCA) at Akure (Latitude 7o 30’N,
Longitude 3o 52’E) in the rainforest belt of Nigeria. There
are two rainy or cropping seasons: April to July (early cropping season) and
August to November (late cropping season). The sites had been under continuous
cultivation to maize and cassava for at least six years and the soils belong
to Alfisol (Oxic Tropuldalf).
There were eight treatments applied to soil on which seedlings of tomato (var.Roma VF) were planted. They were (a) Cocoa hush (CH) + cow dung (CD); (b) CH + poultry manure (PRQ) ; (C) CH + goat manure (GM); (d) Spent grain (SG) + CD; (e) SG+PM, (f) SG+GM; (G) 200 kg ha-1 NPK (15-15-15) fertilizer; and (h) a control (no treatment). Ground CH, SG and the animal manures were air-dried before being mixed at equal rate of 12.5 t ha-1 each to give: 25 t ha-1 for the mixture. Treatments were replicated thrice at each site and applied to early and late crops of tomato. Manure was applied by ring method.
Three week old tomato seedlings were transplanted to the field at 75x50 cm and treatments were applied two weeks after transplanting. Land was manually cleared, disc ploughed and harrowed before planting. The early crop at each site was transplanted in May 2004 while late crop was transplanted in August 2004. There were 66 plants in each 25 m2 plot. Ten plants were selected per plot for determination of height, number of branches and leaf area at 70 days after treatment application. Leaf area per plant was determined using leaf area meter. The number and weight of ripe fruits were taken between 72 and 90 days after treatment application and accumulated.
Leaf Analysis
At 40 days after treatment application, leaf samples were collected per
plot, oven-dried at 80°C for 24 h and ground for analysis. Total N was determined
by micro-kjeldahl method. For P, K, Ca and Mg leaf sample was ashes and extracted
using nitric-perchloric-sulphuric acid mixture. The P was determined using vanadomolybdate
colorimetry, Ca and Mg by EDTA titration and K using flame photometer (Tel and
Hagandy, 1984). The SG and CH were similarly analyzed.
Initial Soil Analysis
In each of the two sites 1 were core samples were collected to 15cm deptly
and bulked, air dried and 2 mm-sieved before commencement of experiment. The
scandy clay loam sorts were analyzed as described by Carter (1993) soil pH in
Ca C12 (1:2 soil-Ca C12 ratio) was determined by wet dichromate oxidation method,
total N by micro-Kjeldhl method and available P was extracted by Bray-1 solution
before molybdenum blue colorimetric. Exchangeable K, Ca and Mg were extracted
using ammonium acetate, K was determined on flame photometer and Ca and Mg by
EDTA titration.
Statistical Analysis
Plant data were subjected to analysis of variance and least significant
difference at 95% level of probability was used to compare mean data on treatment
basis. Data for the two sites were pooled because of similarity.
RESULTS AND DISCUSSION
Chemical analysis data for the test soils are presented in Table 1. The soils were slightly acidic, low in organic matter, total N, exchangeable K, Ca and available P. The evaluation is in respect to standards given for crop production in different ecological zones of Nigeria (Akinrinde and Obigbesan, 2000). The soils and crops of tomato are expected to benefit from application of manures derived from agricultural wastes.
Table 2 shows data on response of leaf N, P and K concentrations of tomato to application of manure and fertilizer treatments. Compared with control, KF and animal manure amended SG and CH increased leaf N and K significantly (p = 0.05). Amended SG and CH also increased leaf P of early tomato (except SG+GM) but the increases were not significant. The overall mean leaf N for the control, NPKF, SG+ manure and CH+ manure were 2.9,4.4, SO and 4.2%, respectively: the values for leaf P were 0.2, 0.4, 0.3 and 0.4%, while values for leaf K were 1.2, 2.6, 2.1 and 3.8%.
The increases in plant nutrients content is attributable to release of nutrients
from the plant and animal wastes. Analysis of SG gave values of 5.18% N, 1.78%
P, 0.07% K, 1.44% Ca and 0.58% Mg: the C:N being 11.1. Analysis data for CH
were 1.83% N, 2.38% P, 4.12% K, 1.19% Ca, 0.44% Mg and C;N of 12.5. The amendment
of the residues with animal manures should have enhanced decomposition and release
of nutrients from the plant residues due to lower C:N of the animal manures
(MoyinJesu and Ojeniyi, 2000).
| Table 1: | Precropping soil chemical properties at Akure, Nigeria |
| Table 2: | Effect of animal manure amended spent grain and cocoa husk on leaf nutrient content of early and late tomato plant |
| SG+CD = Spent grain+Cow dung, SG+PM = Spent grain+Poultry manure, SG+GM = Spent grain+Goat manure; NS: Non Significant, CH+CD = Cocoa husk+Cow dung, CH+PM =Cocoa husk+Poultry manure, CH+GM = Cocoa husk +Goat manure, NPKF = NPK (15-15) fertilizer at 200 kg ha-1 | |
| Table 3: | Effect of animal manure amended spent grain and cocoa husk on growth of the early and late tomato plant |
| SG+CD = Spent grain+Cow dung, SG+PM = Spent grain+Poultry manure, SG+GM = Spent grain+Goat manure CH+CD = Cocoa husk+Cow dung, CH+PM= Cocoa husk+Poultry manure, CH+GM = Cocoa husk+Goat manure NPKF = NPK (15-15-15) fertilizer at 200 kg ha-1 | |
| Table 4: | Effect of animal manure amended spent grain and cocoa husk on fruit yield of early and late tomato plant |
| SG+CD = Spent grain+Cow dung, SG+PM = Spent grain+Poultry manure, SG+GM = Spent grain+Goat manure CH+CD = Cocoa husk+Cow dung, CH+PM = Cocoa husk+Poultry manure, CH+GM = Cocoa husk+Goat manure NPKF = NPK (15-15-15) fertilizer at 200 kg ha-1 | |
Application of animal manure amended SG and CH increased growth parameters (Table 3) and fruit yield (Table 4) significantly (p = 0.05). However the increases in height of late tomato plant were not significant. The mean values of plant height for the control, NPKF, amended SG and amended CH were 69.2, 74.1, 80.5 and 78.3 cm, respectively; the values for number of branches were 4.6, 8.9, 7.0 and 7.2 and values for leaf area per plant were 83.4, 101.9, 106.6 and 114.2, 15.0 and 15.6, while the values for fruit yield were 7.7, 28.3, 34.0 and 38.3 t ha-1. Therefore tomato yield increased in the order control (NPKF (amended SG (amended CH. The fruit yields given by CD, PM and GM amended CH and PM and GM amended SG were similar and significantly higher than value for NPKF (Table 4). The increases in growth and yield of tomato given by animal manure plant residues is consistent with increased N and K concentrations of tomato plant. The highest and similar mean values of yield given by amended CH and SG is attributable to highest leaf K and leaf N recorded for CH and SG, respectively. Analysis data of CH and SG showed that they had relatively high values of leaf K and N, respectively. The CH has been used as source of K for maize (Egunjobi, 1975) the eight treatments compared, CH+PM and SG+PM, respectively gave highest values of fruit yield. This is also consistent with the fact that PM is known to have highest concentrations of N and P and least C:N and C:P ratios compared with GM and CD (Ikpe et al., 2003). The above attributes of PM would have enhanced decomposition of the crop wastes and quicker release of nutrients for tomato uptake.
Amended CH and SG gave higher fruit yield than NPKF. Compared with control, NPKF, amended SG and amended CH increased mean fruit yield by 268, 342 and 397%, respectively. This could be due to more nutrients released from the crop materials such as Ca and Mg.
CONCLUSIONS
Crop wastes such as spent grain and cocoa husk combined with poultry, cow and goat manures at equal rates to give 25 t h-1were effective in. Increasing N and K concentrations, growth and fruit yield of tomato significantly. The amended of the crop residues with poultry manure increased fruit yield than NPK fertilizer. Crop and animal wastes could be combined and used as organic fertilizer. Animal manure amended crop wastes can substitute for chemical fertilizer in cultivation of tomato.