2 Perkara Yang Perlu Diambilkira Ketika Memilih Lokasi Rumah Lindungan

Memilih lokasi yang sesuai untuk rumah lindungan adalah sangat mustahak. Tetapi apakah yang dimaksudkan kawasan atau lokasi yang baik? Ada beberapa perkara yang perlu diambilkira ketika memilih lokasi kawasan untuk mendirikan rumah lindungan hujan bagi projek tanaman secara Fertigasi, Aeroponik atau kaedah penanaman hidroponik yang lain:

1. Radiasi Solar (sinar Matahari) - Kadar kecerahan sinaran Matahari yang cukup sepanjang tahun adalah sangat mustahak untuk pertumbuhan tanaman kerana ia menentukan kadar fotosintesis pokok.
2. Bekalan Air - Air diperlukan untuk sistem irigasi/pengairan tanaman. Lokasi yang dipilih perlulah mudah mendapat bekalan air yang bersih dan sesuai dari segi pH & TDS
3. Ketinggian - Ketinggian lokasi dari paras laut juga menentukan jenis tanaman yang paling sesuai ditanam. Contohnya, tanaman Strawberry tidak sesuai ditanam di tanah rendah di Asia Tenggara tetapi hanya sesuai di tanah tinggi.
4. Microclimate - Ia berkaitan faktor-faktor berikut --> * Latitude - aras laut *Persekitaran yang berhampiran kawasan air yang luas (laut, tasik dll) akan mengurangkan suhu terutamanya di waktu malam *Pokok-pokok, bukit bukau & halangan lain *Awan dan kabus *Kawasan angin lintang yang tinggi - ia boleh menyedut haba *Habuk/pasir yang berterbangan * Salji
5. Habitat atau kehadiran populasi serangga - Pemerhatian bukan sahaja terhadap kehadiran serangga perosak, tetapi juga serangga pemangsa yang bermanafaat untuk tanaman untuk kawalan biologi
   
6. Keadaan Potografi kawasan - Tapak lokasi haruslah rata dan tidak melandai terutamanya jika hendak menggunakan setup pengairan automatik.
7. Kemudahan asas - Bekalan elektrik, telefon, dan perparitan
8. Kemudahan jalanraya - Untuk transportasi bahan-bahan pertanian, binaan & hasil tanaman
9. Orientasi Utara-Selatan - Kedudukan orientasi sudut kompas ini adalah penting dari segi *untuk mengelakkan struktur binaan rumah lindungan itu sendiri menjadi bayang-bayang dan menghalang sinaran matahari kepada tanaman *Baris-baris tanaman akan menerima kadar cahaya yang sama untuk mendapatkan hasil yang sekata (uniform)
10. Keupayaan untuk pembesaran - kawasan tapak mestilah cukup besar untuk menampung kemungkinan melakukan pembesaran dengan membina lebih banyak rumah lindungan
11. Kemudahan bekalan buruh/pekerja
12. Pengurusan penempatan - Penempatan/rumah untuk pengurus ladang atau pekerja haruslah berdekatan dengan kawasan yang hendak dipilih
    

12 Thing To Consider When Selecting Greenhouse Site - Expansion, Labour & Management Residence

10. Capability of Expansion – Purchase more land than you anticipate using in the beginning so that you have the ability to expand your operation. Locate the initial greenhouses such that future expansion will utilize the land area most efficiently.

11. Availability of Labor – The grower needs people who will want to work as laborers and who are “trainable” to become a retainable workforce.
*Such skills included pruning/training the plants and harvesting/packing the fruit.
*SPECIALTY LABOR will include people with additional training in such fields as plant production, plant nutrition, plant protection (insects and diseases) computers, labor management, marketing, etc. These may or may not be part of the regular workers, but could be call on as consultants as needed.

12. Management residence – The grower/manager residences should be close to the
greenhouse so that they can get to the greenhouse quickly in case of emergencies.

12 Things To Consider When Selecting Greenhouse Site - Utilities, Roads & North-South Orientation

7. Utilities – Availability of utilities should include telephone service, three-phase electricity and fuel for heating and carbon dioxide generation.*Note that, when compared to propane, electricity or fuel oil, natural gas is the most economical heating energy source.

8. Roads – Need access to good roads to transport the “product”. Good roads close to a large population center, or to a brokerage center aids wholesale and retail marketing.

9. North-South Orientation – The greenhouse should be oriented north-south, AND the
plant rows within the greenhouse should be oriented north-south. *If oriented north-south, the greenhouse structure itself will not cast consistent shadows on any one area of the plants throughout the day. *If oriented north-south, the plant rows will receive equal light throughout the day. If oriented east-west the south most rows (in the northern hemisphere) will shade the rows to the north.

12 Things To Consider When Selecting Greenhouse Site - Pest Pressure & Level and Stable Ground

5. Pest Pressure – Choose a site away from existing agriculture production areas which could harbor insect pests in the fields. Insect pests of concern include white flies, aphids, spider mites and thrips (see here for pests and control methods).

6. Level and Stable Ground – The ground upon which the greenhouse will sit must be

• Graded for routing surface water to a drainage system or a holding pond. (Typical grade = ½ % or a 6 inch drop over a distance of 100 feet.)
• Compacted such that there will be no settling of the site after the greenhouse has been constructed.

12 Thing To Consider When Selecting Greenhouse Site - Elevation & Microclimate

3. Elevation – will effect the summer maximum and the winter minimum temperatures.
Choosing an appropriate elevation will minimize heating costs in the winter and cooling costs in the summer. Example: In Arizona tomato production is most economical between 4000 and
5000 feet (1220m-1520m). Below 4000 feet cooling costs in summer will be more whereas above 5000 feet heating costs in the winter will be more. Lower elevations might be suitable for peppers or cucumbers.

4. Microclimate - Factors which falls in microclimate considerations:

• Latitude – Unless the global climate changes drastically, sea level at the poles will be colder than sea level in the tropics… latitude makes a difference!
• Large bodies of water – will tend to moderate the temperature (e.g., coastal areas tend to have smaller day/night temperature differences than inland areas)
• Trees, mountains or other obstructions – may cast shadows on the greenhouse, especially in the morning or afternoon hours. Mountains can also effect wind and/or storm patterns.
• Clouds and fog – Note that certain areas (e.g., on the lee side of certain mountain ranges, or near coastal regions) may develop clouds or fog during certain times of the day or year that will reduce potential sunlight.
• High Wind Areas – High winds can “suck” heat away from the greenhouse structure and therefore increase the heating energy demands.
• Blowing dust/sand – High winds can “kick up dust or sand”, especially in desert regions, which can damage some greenhouse glazings.
• Snow – The weight of heavy, wet snow on a greenhouse could crush it. However, high winds in snow areas can also blow snow up against the greenhouse structure (snow drifts) and cause damage to it. This danger can be reduced by using windbreaks (trees, snow fences, etc.).

Things To Consider When Selecting A Greenhouse Site - Solar Radiation & Water Supply

Selecting a “good” site for the location of a greenhouse is crucial. But what constitutes a “good” site? There are several things that should and must be considered in order to increase the
chances of a successful operation and business.
12 THINGS TO CONSIDER WHEN SELECTING A GREENHOUSE SITE:
1) Solar Radiation – Plants require sunlight in order to perform photosynthesis. When plants experience cloudy days their photosynthetic rates, and therefore their ability to grow and yield a product, such as tomatoes, cucumbers, peppers, etc., will be reduced. Therefore, a region and location with high light intensity year-round is desired.

2) Water – Water quantity and quality is crucial. Water will be needed for irrigation (maximum of 1 gal/plant/day for tomatoes). Water will be needed for the evaporative cooling system and can equal or exceed the irrigation water amounts (10,000 – 15,000 gal/acre/day). In the past, excess irrigation and bleed-off water from the evaporative cooling system was allowed to “run off” onto the ground adjacent to the greenhouse (with a rec. minimum percolation rate into the soil of 1”/hr.).
*HOWEVER, due to more strict regulations and a desire to avoid ground water contamination with high concentrations of salts, large greenhouses are now recirculating the nutrient solution.
*THEREFORE, excess nutrient solution should be recycled and/or mixed with the cooler bleed-off water and redirected onto designated areas, such as grass, shrubs, trees/windbreaks, etc.
*No matter what the source of the water, a water analysis should be done.
*Note: Sea water = 32,000 ppm (mg/l) VS Tucson water = 200-400 ppm.
Note: 640 ppm TDS (total dissolved solids) = 1 mmhos/cm or 1 mS/cm.

*Desired salt levels in the source water:
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