Wednesday 29 August 2012

Description of the experiment and why it is being conducted


We had to plant four spinach seeds in four different types of soil medium:

1.       C1 : Sand

2.       T1 : 50% compost and 50% Sand

3.       T3 : 100% worm compost

4.       T4 : Sand with worm tea ONLY given once

Procedure for pot trail planting:

1.       Determine soil texture by following the texture feel test

2.       Fill two 200ml pot with soil

3.       Soak soil by adding water to soil until saturated

4.       Sow seeds at 1cm depth (4 seeds per pot)

5.       Add 5g tea extract fertiliser to ONLY 1 pot. Unfertilised pot will serve as control

6.       Place pots in sunny conditions

7.       Be sure to keep soil moist

8.       Monitor emergence of seedlings and growth

For this procedure we need to monitor our plants for 10 weeks during this period we need to record the plant growth, soil changes and plant leaf changes for example: blotches, deformations and insects etc. After 10 weeks we need to write a report and present this to the class in our practical groups. The aim of this project is to ensure that we are able to identify the nutrient deficiency symptoms, the importance of these elements for Crop Production, the plant requirements, suitable fertilizer and the symptoms of toxicity.    

For the second part of the practical we needed to conduct the  following procedure to determine the Exchangeable cations (EC) and pH of the four soils and worm tea extract:

1.       Sieve and collect sand, 50% sand and 50% compost, 100% compost and worm tea extract

2.       Add 50ml distilled water to all the mediums

3.       Stir all the mixtures for 3 minutes

4.       Allow to stand for 1 minute

5.       Take the pH and EC reading of the mediums

6.       Measure the pH and EC of the tea extract  

This experiment will help us to determine why some soils have delivered better results (plant growth) compared to another soil. This could be because of a high Exchangeable Cations or pH. Some plants also prefer having a slightly acidic soil this will indicate to us if this is true or not. This experiment also tells a bit more about the soil that we are currently farming to deliver results in growth.

 

Description of the Analysis thus far


Description of analyse thus far

We planted spinach seeds which thus far have germinated. The first date we recorded data was on the 7th of August. The leaves have so far sprouted. We have four pots to observe and this week all measurements were under 2.3cm.

A week later on the 14th of August the plants have almost doubled in size. Thus far the plants are growing optimally and the presence of weeds is also now visible.

On the 21st of August we recorded data once again. We observed that the plants have doubled in size once again and measurements have shot up the highest reading being 7cm of T1 and T3. Bugs were also present at this viewing.

A reading was taken on the 28th of August. The plants have now been in the four different mediums for a little over a month. Our top left plant of our ‘control pot’ still hasn’t shown any sign of germination. We have also observed weeds in all four pots, C1 has presence of grass, T4 contains moss on the soil surface and black spots were seen on the leaves of C1 and T1

Why the specific analysis was conducted

The analysis was conducted to determine which soil mediums the seeds would grow best in. These include Sand, 50% Sand : 50% Compost, Sand with worm tea extract . By doing this experiment we can establish a favourable soil type  for the spinach seeds to grow in. We also conducted the EC and PH of each medium  at the end of the experiment we will be able to see  which soil's EC and PH delivered the best growth for the spinach. We can use this for future reference when planting the seedlings again. Therefore in the future we will be able to use the correct soil medium, with the favourable EC and PH to have optimal growth of our seeds. This will help when farming on a larger scale, with different crops. Farmers should conduct  these experiments and analysis before planting the specific crop. Therefore they will beable to save money  and increase productivity of the crop.

Results of the analysis


Results of analysis:

The mixture of compost and soil (50/50) was the first to produce and sprouts and soon after was the 100% compost was second to show any sign of sprouts.

Weeds and grass first showed their presence on 7 August 2012 in all the control, T1, T3, T4 pots and since then have grown at an alarming.
Date photo taken: 2012/08/21



Strange moss has grown in the T4 pot.
Date photo taken: 2012/08/21


The overall average growth of the plants has increased significantly in the intervals of a week of recordings.


 

 
 

On the 21 August 2012 there was presence of insects and white blotches on the leaves. We also found small black dots beneath the leaves.
Date photo taken: 2012/08/21


The pH recording of the 100% soil, 50/50 mixture, 100% compost and tea extract were very similar. In the graph is the recorded pH readings and the temperature of the substances.
 

 

The EC reading and temperature readings are shown in the graph. The graph shows the constant temperature and also the extreme differences between all the substances, where the extract has the highest EC which is measured in uS and the sand which has the lowest.
 
 
EXTRA ILLUSTRATIONS - GRAPHS
 
Results for pH, EC and Temperature of Soils as indicated below:
 
 
 
 
 
 
 
 
 

Plant Nutrient Requirements


Best soil for growing spinach

Choosing the best possible soil to grow your spinach will guarantee an improvement in the flavour and quality of your crop. The soil that you choose to grow your spinach in requires a specific pH range and has to be rich in macronutrients. The most important of which is nitrogen.

 

Optimum soil conditions for spinach

Soil type: Loamy or sandy loam

pH range: 6.2 to 6.9

Nutrients: high nitrogen levels required

 

Soil pH range for spinach

Maintaining the correct pH range is vital in growing tasty spinach plants. It is very important to keep the pH within the 6.2 – 6.9 range. Any more acidic or alkaline will result in your plants growing ineffectively. It is known that spinach is very sensitive in acidic soils.

 

Soil nutrients for growing spinach

Spinach requires a very high level of nitrogen to grow successfully. To obtain high nitrogen content in your soil, a high nitrogen fertilizer may be added to the soil before seeding. Nitrogen makes for a rich tasting and dark green spinach. If the spinach leaves are becoming brown or yellow, this may be a sign of nutrient deficiency.

 

Nutrient Deficiency Symptoms


Common Nutrient Deficiencies in Spinach

1.       Potassium

This nutrient is important for transporting of water within the plant

Symptom: Browning at leaf tips older leaves first then as the problem becomes worse the leaves will get brown (dead) spots between leaf veins.   


2.       Nitrogen

This nutrient is involved in the formation of proteins and plant growth

Symptoms: The older leaves are affected first because the nutrient moves from the old to the new as it tries to grow. The plant will eventually become a pale green or yellow colour with stunted stems growth.

The leaf turns light green then yellow, including the veins. The leaves will then become smaller, thinner as the disorder advances the leaves will develop dead spots and areas. Growth of the plant will slow and eventually stop if the disorder is not corrected

 

3.       Magnesium

Symptoms: Older leaves yellow with dark green veins, pale green colour overall.

The deficiency begins with mottled yellow areas on the leaf which develops between the leaves veins.



This deficiency is often confused with a potassium deficiency

 

4.       Phosphorous

This is needed for nucleic acid activity

Symptoms: Slowed growth and becomes bluish green in the older leaves first especially under leaf.


Seldom deficiencies in spinach

Secondary Nutrients:

5.       Calcium

Symptoms: The old leaves become wrinkled and curled while the new leaves also will remain curled and a light green band will occur along green margin.



 

6.       Zinc

Symptoms: Younger leaves become yellow and holes appear near the veins of the upper surface of mature leaves. The main veins remain green.

7.       Boron

Symptoms: Effects the mature tissue, both the pith and the epidermis of stems is affected therefore causing the stem to become hollow or roughened .The leaves of the plant is usually brittle and tend to break easily.

8.       Molybdenum

Symptoms: The entire plant will become a yellow colour similar to nitrogen deficiency but does not have the reddish colour behind the leaf. The leaf becomes a mottled this causes yellowing between the veins but the leaves remain green.

 

9.       Manganese

Symptoms: First found in the older leaves then in the younger leaves. It begins with a light colour change (Chlorosis) in the young leaves and in the netted veins of the mature leaves. As the stress increases the leaves become a gray metallic sheen, dark freckled and dead areas occur along the veins.



10.   Sulphur

Symptoms: The plant is usually stunted or reduces growth but there are no dead leaves but general yellowing of young leaves.



11.   Iron

Symptoms: The deficiency begins in the youngest leaves of the plant this eventually causes the entire plant to become a pale yellow. The bleached areas often become dead spots until the entire plant will become almost white.

 

12.   Chloride

Symptoms: The most common sign is pale yellow discolouring and wilting of young leaves. In mature leaves the upper side of the leaf becomes bronze.

13.   Copper

Symptoms: The leaves are curled and petioles bend downwards

Recently matured leaves show netted, green veining with areas bleached to a whitish    gray. The leaves tend to bend downwards with brown spots.

Suitable fertiliser application of each element


 



Suitable fertilizer application of each element

COPPER – Cu
 
http://www.spectrumanalytic.com/support/library/ff/Cu_Basics.htm
ZINC – Zn
http://www.soils.wisc.edu/extension/pubs/A2528.pdf
 
BORON – B

http://www.soils.wisc.edu/extension/pubs/A2522.pdf
 

IRON – Fe
Fe-DTPA,
Fe-EDDHA,
Fe-EDTA.
Ferrous sulfate (FeSO4.2H2O)
 
MOLYBDENUM – Mo

http://www.spectrumanalytic.com/support/library/ff/Mo_Basics.htm
MANGANESE – Mn

http://www.spectrumanalytic.com/support/library/ff/Mn_Basics.htm
CHLORINE - Cl

http://www.spectrumanalytic.com/support/library/ff/Cl_Basics.htm
 
 

Toxicity symptom in spinach
 

COPPER – Cu

The two most common symptoms is undersized root growth and leaf chlorosis

 

ZINC – Zn

Chlorosis of the younger leaves which in extreme cases could result in the leaves turning red.

 

BORON – B

Spot-like, striped or blotchy yellowing on the leaves will occur

 

IRON – Fe

Dark green foliage, stunted top growth and root growth, as well as leaf bronzing which causes dark brown to purple spots on the foliage.

 

MOLYBDENUM – Mo

Marginal leaf scorch and abscission as found in typical salt damage. Yellowing or browning of leaves and depressed tillering.

 

MANGANESE – Mn

Chlorosis and necrotic lesions on old leaves, dark-brown or red necrotic spots

 

CHLORINE - Cl

Leaf margins are scorched and abscission is excessive. Leaf/leaflet size is reduced and may appear to be thickened. Overall plant growth is reduced. Chloride accumulation is higher in older tissue than in newly matured leaves. In conifers, the early symptoms are a yellow mottling of the needles, followed by the death of the affected needles.