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INVESTIGATING WHETHER IT IS STILL NECESSARY TO APPLY PHOSPHORUS FERTILIZER AT THE RECOMMENDED

RATE IN MAIZE PRODUCTION AT BUNDA CROP SCIENCE STUDENTS’ RESEARCH

FARM

BY

CHARLES SOKO

SUPERVISOR

DR M.W. LOWOLE

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Presentation outline

Introduction

Problem statement and justification

Objectives

Hypotheses

Materials and methods

Data collection and analysis3

Introduction

Maize (Zea mays L) is a staple food crop and is grown by more than 90% of farm households in Malawi (Malawi Strategy Support Program 2011)

However the cost of maize production is high for most subsistence famers as most soils in Malawi require additional supply of fertilizers (NSO, 2005).

Among the essential macro nutrients required for maize production are nitrogen and phosphorus at 92kg/ha and 21kg/ha respectively (MoAFS 2012)

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Role of Phosphorus (P)

P is one of the most important nutrients for higher grain yield in larger quantity (Chen et al. 1994)

P is a key element in metabolism as it is a component of ATP hence controls energy storage in living things (Chavarria 1981).

Introduction cont…

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Introduction cont…

Immobility of P

When P fertilizers are applied to the surface of the soil, P accumulates in the surface layers of the soil (Ludwick 1998)

• In most soils there is little movement of P (Chavarria 1981).

• Due to rapid precipitation of P in the soil, leaching of P is negligible (Ludwick 1998)

As a result of these factors, P is known to be an immobile nutrient and tends to accumulate in the soil.

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Problem statement and justification

Phosphorus fertilizers have been applied over a prolonged time (over 10 years) at the crop science students’ research farm.

Since P is an immobile nutrient, it might have accumulated in the soils to sufficient levels.

In order to prevent wastage of resources it might be wiser to minimize the application rate on P fertilizer to reduce the cost of production on fertilizer inputs.

This will result in obtaining maximum benefit with minimum dose of fertilizer application rate.

Minimizing the rate of application will also help prevent contamination of ground water supplies as a result of erosion of top soil containing the accumulated P.

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Objectives

Main objective

To investigate if it is still necessary to apply P fertilizer at the recommended rate in maize production at the students research farm.

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Specific objectives

To determine the effect of different rates of P fertilizer on maize growth

To determine the effect of different rates of P fertilizer on maize grain yield

To determine the effect of different rates of P fertilizer on maize biomass.

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Hypotheses

Ho: Different rates of P fertilizers have the same effect on maize growth.

Ho: Different rates of P fertilizers have the same effect on maize grain yield.

Ho: Different rates of P fertilizers have the same effect on maize biomass.

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Materials and Methods

Site description

The experiment is being carried out at Bunda College Crop Science students’ research farm during the 2014/2015 growing season.

Latitude of 14o 35’ S, longitudinal 33o 50’ E

Altitude of 1159 m above sea level

Mean annual rainfall of 1031mm.

Mean temperature of 18oc -27oc 11

Materials and Methods

Materials

Phosphorus fertilizer (Triple Superphosphate)

Nitrogen fertilizer (Urea)

SC 403 (Kanyani) maize variety• early maturing

• 5 000 kg/ha

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Materials and methods cont…..

Methods

SC 403 (kanyani) maize variety has been planted at 0.25m apart and 1 seed per station.

Different rates of P fertilizer have been applied to the plots.

The rate of N fertilizer (Urea) has been kept constant.

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Experimental design

The experiment has been laid out in a Randomized Complete Block Design (RCBD).

5 treatments, 3 replicates

15 plots

5 ridges/plot, 5m long each and spaced at 0.75, with gross plot of 18.75m2 and net plot of 6.5m2.

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Experimental design cont……

Treatments

T1 = 92kg/ha N and 0kg/ha P

T2 = 92kg/ha N and 10kg/ha P

T3 = 92kg/ha N and 20kg/ha P

T4 = 92kg/ha N and 30kg/ha P

T5 = 92kg/ha N and 40kg/ha P15

Experimental design cont……

Field lay out

BLOCK 1 BLOCK 2 BLOCK 3

T2

T5

T3

T1

T4

T2 T3

T3

T1

T4 T5

T2

T4

T5 T116

Data collection and analysis

Data collection

For each objective the following parameters of agronomic data will be collected:

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Objective Data to be collected

1.To determine the effect of different rates of P

fertilizer on maize growth

Germination percentage Plant heights Number of days to 50% tasselling Chlorophyll levels Cob length

2. To determine the effect of different rates of P

fertilizer on maize grain yield

Grain yield Stand count at harvest Number of cobs per plant The weight of 100 seeds after harvesting

and after oven drying Number of grains per cob

3.To determine the effect of different rates of P

fertilizer on biomass.

Stand count at harvest biomass

Data collection and analysis cont…

Data collection

Soil samples will be analyzed for the following;

Available phosphorus

Total nitrogen

Soil pH

% organic matter

Soil texture

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Data collection and analysis cont…

Data analysis

Yield estimation will be explained by the following statistical model

Yijk= μ +βi +τj +εijk

Where: Yij = total yield

µ = overall mean

βi = block effect

τj = treatment effect

εijk= the error term

The data collected will be subjected to analysis of variance (ANOVA) using GENSTAT statistical package.

To separate means that are significantly different, Tukey test will be used. 19

End of presentation

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