Farmers Review Africa Sept/Oct 2018 FRA - September - October 2018 digital 5 | Page 58

FEATURE quantities of nutrients; whether they have them or not depends on the particular soil they’re growing in. Thus, the only way to know the precise N-P-K ratio you need is to test your soil and then formulate a custom fertilizer based on the nutrients that are deficient. On the other hand, it doesn’t have to be that complex. Nitrogen availability is almost always the limiting factor in plant growth and health. Which is why the N number is usually highest. In most cases, you’ll have success-using products with an N value in the 5 to 10 range and P and K values of 1 to 4. Using products with nitrogen concentrations above 10 percent greatly increases the likelihood of over-fertilizing, which can harm the plants. Furthermore, any fertilizer that isn’t readily absorbed will eventually leach away and pollute nearby water resources. The one exception are fertilizers for special plants like citrus, palms, orchids and African violets. These typically contain additional micronutrients (beyond N, P and K) that are helpful for growing those particular species. Forms of fertilizer Choosing from among the three forms of fertilizer is largely a matter of personal preference, though there are a few practical considerations. The most important has to do with how quickly the nutrients are released. Liquid nutrients are available immediately, while granular or pelleted fertilizers last longer in the soil. Spikes are really designed for houseplants; it isn’t practical or economical to put a spike in the ground next to every single plant in a large garden Bulk bags of pelleted or granular fertilizers are by far the most economical option, though the organic ones are notorious for inciting pets to sniff, dig and roll in the tantalizing animal products that they contain. Liquid fertilizers are an option to prevent this, though you can always convert granular fertilizers to liquid form by grinding them up and soaking them in a bucket of water for a few days. Advertisers’ index TO ADVERTISE IN FARMERS REVIEW AFRICA | CALL: [phone], Email: [email protected] Agrico.............................................................................................OBC Neptun Boot.................................................................................IBC BMG world...........................................................................................9 Petkus..................................................................................................33 Cresent Foundry...............................................................36,44,51 Dunlop................................................................................................37 Iriggation Show...............................................................................48 Andres Pintaluba............................................................................53 RJ Obrien............................................................................................30 Joined Specialised Farming..........................................................4 Shell.......................................................................................................15 KSB Pumps & Valves....................................................................11 TSGC.................................................................................................IFC 56 |September - October 2018