Ginger cultivation in grow bags: High yield and quality with minimal fertilizer

Ginger is now cultivated in polyhouses using precision methods and in open fields using conventional methods, as well as in grow bags. Grow bag cultivation requires careful attention to soil, seed, and growing conditions.

The ideal soil for ginger cultivation should be rich in organic matter, fertile, well-drained, and well-aerated. The soil pH should ideally be between 6 and 7. If the soil is too acidic, lime should be added to reduce acidity. It's crucial to adjust the pH based on soil testing, as high acidity favours harmful microorganisms over beneficial ones.

As ginger is a heavy feeder, scientific fertilizer application is essential. Organic and bio-fertilizers should be used based on soil (or potting mix in grow bag cultivation) testing. Ginger grows rapidly during the first four months, then slows down for the next three months before growth stops and the stalk dries. Therefore, fertilizer application should be completed within the first four months. The most important nutrients for ginger are nitrogen, potassium, phosphorus, calcium, and magnesium. Zinc sulfate can be added if zinc deficiency is observed.

A study conducted at Kerala Agricultural University (KAU) from 2016-2018, funded by the Central Government, investigated precision grow bag ginger cultivation in polyhouses. High-yielding varieties like Athira, Karthika, and Ashwathi, developed by KAU, were used. Planting material included 20-gram ginger rhizomes, one or two-budded pre-treated seedlings, and micro-rhizome plants. A 40cm x 24cm x 24cm grow bag was filled with a mixture of soil, sand, dried cow dung powder, and coir pith in a 1:1:1:1 ratio. One planting material (20-gram ginger rhizome/pretreated seedling/micro-rhizome plant) was planted per grow bag. Excellent yields in precision farming were obtained using the KAU-recommended fertilizer application of N, P2O5, K2O at 75:50:50 kg/hectare using fertigation. Water-soluble fertilizers (19:19:19, 13:00:45, 12:61:00, and urea) were applied in installments, mainly during the first four months. The study also found that the ginger growth period could be somewhat regulated by adjusting the watering schedule. Yields of up to 1.5 kg of fresh ginger per grow bag were achieved.

Grow bag yield depends on several factors: variety, weight of planting material, grow bag size, potting mix composition, fertilizer application, and watering. KAU recommends less than 3 grams of NPK fertilizer per plant. All phosphorus and half the potash can be added as basal fertilizer before planting. Half the nitrogen should be applied after one and a half to two months, and the remaining half along with the other half of potash after three to four months. These quantities may be adjusted based on soil (potting mix) testing. When adding fertilizer, care should be taken to avoid damaging the rhizomes. This is easier with water-soluble fertilizers. Adding Trichoderma-enriched cow dung powder and neem cake mixture to the planting hole and mulching the grow bag after planting help prevent pests and diseases. Solarization of the potting mix also helps prevent pests and diseases.

Due to climate change, careful attention should be paid to watering and shading. Moderate rainfall at planting and abundant rainfall during the growth period are beneficial. Rainfall should cease one month before harvest. Supplemental watering is necessary if rainfall is insufficient during the growing season. Ginger prefers moderate shade (25%), but excessive shade should be avoided. High ambient temperatures are detrimental; shade nets may be used if necessary.

It's best not to reuse the potting mix, as ginger depletes soil nutrients and prevents the spread of soil borne diseases. When harvesting, it's crucial to remove all rhizomes from the soil to prevent the spread of diseases.

Grow bag cultivation offers the advantage of producing pest- and disease-free ginger rhizomes, ensuring export-quality, chemical-free produce. It also allows for off-season production and market-driven yield adjustment. Grow bag cultivation is also beneficial for planting material production and the propagation of high-yielding varieties.
Address: Professor (Retd.), Kerala Agricultural University, Thrissur – 680 651