PhD.

An investigation entitled “Precision farming in banana (Musa AAB Nendran) for productivity enhancement” was undertaken during 2014-2017 to assess the influence of land management practices and lime application on growth and yield of banana, to standardize the fertigation schedule for yield improvement, to work out the economics and to study the nutrient dynamics under soil and fertigation systems of nutrient application. The study consisted of two experiments carried out simultaneously for two years from March 2015 to May 2017 in the farmer’s field at Pirappancode, Thiruvananthapuram.
The first experiment on “Soil management and fertigation studies in banana” was laid out in split plot design with 12 treatment combinations and two controls each replicated thrice. The main plot treatments were the combinations of land management practices (l1- conventional land management and l2- land management for precision farming) and lime application{c1 – as basal at the time of pit preparation and c2 – applied in 2 splits (1/2 basal+1/2 at 4 MAP)} and the sub plot treatments were three levels of fertigation (n1-60 % recommended dose (RD) of N & K; n2- 100 % RD of N & K and n3-140 % RD of N & K). The two controls maintained were KAU adhoc recommendation for precision farming (control 1) and KAU POP (control 2). Lime requirement was calculated based on initial pH and applied as per the treatment. As the P status of the soil was high, P was applied @ 75 % RD for all treatments except control 1. Basal application of FYM @ 15 kg plant-1 and two bunch sprays with 3 % SOP were given uniformly for all the treatments.
Precision land management practice (L2) improved growth attributes viz. LAI and total dry matter production (TDMP) and yield attributes like number of fingers in D hand (9.89) during first year and number of fingers bunch-1 (67.71) during second year. L2 also improved quality attributes like TSS and total sugar during second year and reducing sugar and total P uptake during both the years. Pooled analysis indicated the superiority of precision land management practice on yield (28.3 t ha-1).
Basal application of lime (C1) resulted in higher LAI, TDMP, number of fingers bunch-1 (67.78), number of fingers D hand-1 (11.08), D finger weight (163.26 g), bunch weight (11.27 kg) and total K uptake during second year. Quality parameters viz. TSS, and sugar acid ratio during first year and pulp peel ratio during second year were also more for C1. Basal application of lime significantly increased the second year yield (28.19 t ha-1) and pooled yield (28.96 t ha-1).
Higher growth attributes viz. LAI and TDMP and NPK uptake were observed with N2 during first year and N3 during second year. However, N2 and N3 were on par with respect to N uptake during first year and P uptake during second year. Among yield attributes, weight of D finger (223.71 g) was more with N2 during first year and higher number of fingers bunch-1 was obtained with N2 (66.66) and N3 (68.19) during second year. Fertigation of 60 % RD of N & K significantly improved fruit quality. Pooled yield was higher with fertigation of 100 % and 140 % RD of N & K (28.68 t ha-1 and 27.63 t ha-1 respectively).
All treatment combinations resulted in improved growth and yield over control 2. Precision land management and basal application of lime with fertigation of 60, 100 or 140 % RD of N & K recorded higher yield (30.38, 30.87 and 28.77 t ha-1 respectively). Fertigation treatments and adhoc recommendation resulted in yield improvement by 30.83 % and 21.61 % respectively over soil application.
Precision land management practices and fertigation of 100 % RD of N & K significantly improved water use efficiency (WUE) and water productivity during the first year while fertigation of 100 % and 60 % RD of N & K recorded higher water productivity application during second year. Application of entire quantity of lime as basal enhanced WUE during both the years. Drip irrigation enhanced WUE and water productivity over basin irrigation. Compared to soil application of 100 % RD of N & K, fertigation with the same nutrient level resulted in higher nutrient use efficiency and agronomic efficiency.
All treatment combinations recorded higher gross income, net income and B: C ratio when compared with controls. Among the combinations, precision land management with basal application of lime and fertigation with 60 % RD of N & K recorded higher B: C ratio (3.75).
The second experiment on “Nutrient dynamic studies in banana” was carried out with the treatment combinations involving fertigation of 100 % RD of N&K (l1c1n2, l1c2n2, l2c1n2 and l2c2n2) of the first experiment along with controls. Observations on pH, organic carbon (OC), primary, secondary and micro nutrient status in both soil and plant were taken at bimonthly interval.
Dynamics on soil pH duirng first year and NH4-N and S during both the years indicated an initial increase upto 4 MAP followed by a decline at 6 MAP and again a slight increase at harvest stage of the crop. However for pH during second year and K content during first year, a slight decrease was noticed towards the harvest stage. In general, an increasing trend in NO3-N content in the soil was observed from initial stage to harvest stage of the crop. An increasing trend in OC and P contents were also observed in the soil. In general, build up of Ca and Mg in the soil was noticed after two years of experimentation.
Changes in soil pH and nutrient content under fertigation and soil application of fertilizers indicated that soil application resulted in higher pH during first year while fertigation enhanced pH during second year especially during grand growth phase (6 MAP). The OC content recorded varying response during both the years. Fertigation resulted in higher NO3-N content in soil throughout the growth stages except at 6 MAP during first year and 6 MAP and at harvest during second year. Soil application of fertilizers resulted in higher K content in the soil throughout the growth stages during first year while fertigation enhanced K availability during early crop growth stages during second year. Availability of Ca and Mg in the soil was more for fertigation compared to soil application of fertilizers especially during grand growth phase. Fertigation improved S availability only at 4 MAP and at harvest.
Correlation study revealed significant and positive correlation of bunch weight with Mg content and N/K ratio in the soil during first year and N, K, Ca and Mg contents and N/P, Mg/P, Ca/Fe and Ca/Mn ratios during second year. Significant and positive correlation of bunch weight was also observed with K, Mn and B contents in the plant during first year and Ca and Cu contents and Ca/Fe and Ca/Mn ratios during second year.
The results of the present study revealed that precision land management practice (deep ploughing to a depth of 50 cm, raised beds to a height of 30 cm, taking pits and planting) along with basal application of FYM, P (based on soil P status) and lime (based on soil pH) and fertigation of 60 % RD of N & K (urea @ 390 g plant-1 and MOP @ 450 g plant-1) is the best management practice to increase yield and profitability of Nendran banana. Fertigation can be given at weekly interval starting from the first month of planting. Soil nutrient dynamics was found to be influenced by rainfall pattern, growth stage of crop and nutrient interactions. In general, fertigation improved the nutrient availability over soil application.