EFFECTS OF <em>POPULUS</em> <em>DELTOIDES</em> LITTER ON ITS SAPLINGS, ASSOCIATED AGRICULTURAL CROPS AND THE PROPERTIES OF AN <em>ALKALI</em> SOIL

Abstract

To study litter effects of poplar (Populus deltoides) on its saplings, associated agricultural crops and on the properties of an alkali soil, a pot study was conducted during 1994 using an alkali soil of pH 9.5 at the Central Soil Salinity Research Institute, Karnal, India. Twelve treatment combinations consisted of three litter levels (0,1:4 and 1:2; litter to soil on volume basis) and four intercrop treatments [no crop, turmeric (Curcuma longa), guinea grass (Panicum maximum) and cowpea (Vigna unquiculata) ] Each treatment was replicated three times in a completely randomised block design. The mean height increment and girth growth of the poplar recorded four months after planting were markedly better in litter-treated soil than in the case of no litter treatment. Similarly, leaf, stem and root biomass values of the poplar were also significantly more when it was planted in litter-mixed alkali soil than in no litter treatment. Further, growth and biomass were also greater when litter was added in 1:2 ratio than in 1:4 ratio. Poplar growth was significantly inferior when its saplings were grown with guinea grass as compared to the no intercrop treatment. Guinea grass yielded nearly 20% more fodder when litter was mixed in 1:2 ratio than in no litter treatment. Litter levels had little effect on P and K concentrations in poplar parts, whereas Na concentration in leaf, stem and root was highest in the no litter treatment. Application of litter caused appreciable reductions in pH and EC and improvements in organic carbon content of the alkali soil. On the other hand, available P and K status of the soil remained unaffected by the litter. The study suggests that addition of poplar litter to alkali soils may be a useful practice when productivity, reclamation and soil fertility aspects are considered.