MSc

The investigation entitled “Nutrient management for coconut based multi-storeyed cropping system in a typical coastal sandy zone” was carried out during January 2014 – March 2015 to develop appropriate cost effective practices for enhancing nutrient use efficiency, productivity and profitability of coconut based multi-storeyed cropping system involving a combination of coconut (C), noni (IC), banana (IC) and long pepper (IC).
The experiment was laid out in Randomized Block Design with 8 treatments and 5 control plots with two replications. The treatments were T1: 100% NPK (C) + 100% NPK (IC), T2: 100% NPK (C) + 75% NPK (IC), T3: 2/3rd NPK (C) + 100% NPK (IC), T4: 2/3rd NPK (C) + 75% NPK (IC), T5: 1/3rd NPK (C) + 100% NPK (IC), T6: 1/3rd NPK (C) + 75% NPK (IC), T7: Basin management (C) + 100% NPK (IC), T8: Basin management (C) + 75% NPK (IC). In addition, sole crops of coconut (T9), long pepper (T11), banana (T12) and noni (T13) were maintained as control plots under 100% NPK besides sole crop of coconut (T10-basin management).
The results of the field experiment revealed that all the growth parameters in long pepper were significantly influenced by treatment effects. The treatment T2 at 4 MAP and T3 at 8, 10 and 12 MAP; T8 at 12 MAP; and T2 at 6 MAP, T3 at 8, 10 and 12 MAP recorded significantly higher values of total vine length, number of branches per vine and total number of leaves per vine respectively. Total spike number per plant, total fresh and dry spike yield and total alkaloid content also showed significant difference due to treatment effects and the treatment T3 recorded the highest value. Nutrient content of leaf and fruit, dry matter production per plant and physiological parameters were not significantly influenced by the treatment effects.
In banana, biometric characters, yield components, yield, plant nutrient status and physiological parameters were found to be unaffected by treatment effects.
However, the performance of banana in multi-storeyed cropping system was found better compared to sole cropping. The highest bunch weight was recorded in treatment T3.
The treatment T3, recorded the highest number of fruits and fruit weight in noni. Nitrogen content in noni fruit was significantly influenced by the treatment effects and the highest per cent was recorded in T3. Litter fall in noni was unaffected by treatment effects but the phosphorus accumulation in soil through litter fall was found to be significant and the treatment T4 contributed the highest quantity of phosphorus to the system. Among the physiological parameters, leaf temperature showed significant influence and the treatment T13 recorded the highest leaf temperature while the treatment T8 recorded the lowest value. Studies on nutrient release pattern of noni leaf litter revealed that 53.3% N, 81.8% P and 61.9% K were released in to the system over a period of seven months.
Pooled analysis of the productivity of coconut over a period of three years confirmed the significance of the treatment T8 which was on par with T7. With respect to copra content also, the treatment T7 registered the highest value. Plant analysis data showed that nutrient concentration in index leaf was unaffected by treatment effects except sulphur.
The treatments significantly influenced the maximum water holding capacity of soil and T8 recorded the highest value. Available P2O5, Ca, Mg and Mn in soil were significantly influenced by the treatment effects and the highest values were recorded in T3, T8, T11 and T4 respectively. Rhizosphere microflora was enumerated and the highest number of bacteria, fungi and actinomycetes were recorded in T8, T11 and T12 respectively. Total energy output was estimated in the cropping system and the highest output was registered by the treatment T3 which was on par with T8. Economic analysis of the system revealed that gross returns, net returns and B:C ratio
were significantly influenced by treatment effects and the highest values were recorded in T8.
The treatment T8 ( Basin management of coconut with in situ green manuring, recycling of palm waste, FYM application @ 50 kg + 5 kg ash + 25 g Azospirillum per palm per year combined with the application of 75% of the recommended dose of NPK each for the component crops viz. noni, banana and long pepper) was found worthwhile for popularization in relation to sustainable yield index, partial nutrient balance with respect to P & K and BCR for coconut based multi-storeyed cropping systems of the coastal sandy zones.