INFLUENCE OF LONG-TERM APPLICATION OFFERTILIZERS ON WEED FLORISTIC DIVERSITY IN MAIZE–WHEAT CROPPING SYSTEM UNDER MID HILL CONDITIONS OF HIMACHAL PRADESH.
Loading...
Date
2019-07-16
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CSKHPKV, Palampur
Abstract
The study was undertaken in an ongoing long-term fertilizer experiment under the aegis of AICRP- LTFE, Department of Soil Science, CSK HP Krishi Vishvavidyalaya, Palampur. There were 9 weed species in maize during 2018 and 10 weed species in wheat during 2017-18 and 13 during 2018-19. Digitaria sanguinalis, Ageratum conyzoides and Eragrostis pectinacea were the major weeds constituting 48.0, 33.0 and 6.0 per cent, respectively, of the total weed flora in maize. Polygonum plebium, Anagallis arvensis and Phalaris minor were the major weeds in wheat constituting 47.0, 18.0 and 16.0 per cent, respectively during 2017-18 and 34.0, 14.0 and 13.0 per cent, respectively during 2018-19. In maize, Shannon Weiner index, Simpson’s index of diversity and Simpson’s reciprocal index were highest for 100% NPK and lowest for 100% N. Population of broad-leaved weeds was significantly affected by fertility treatments. Their population was lowest in 100% N being statistically at par with 150% NPK, control, 100% NP, 100% NPK + lime, 100% NPK (-S), 100% NPK and 100% NPK + HW. Whereas, population of sedges was lowest in 100% NPK which was statistically at par with all other fertility treatments except 50% NPK and 100% NPK + lime. In wheat, Shannon Weiner index, Simpson’s index of diversity and Simpson’s reciprocal index was highest under 100% NPK + lime or 50% NPK and lowest in 100% NPK /100% NPK + HW during 2017-18 and 150% NPK during 2018-19. Population of broad-leaved weeds in wheat was not significantly affected during both the years. Lowest population of grassy weeds was recorded in 100% N during both the years being statistically at par with all other treatments except 50% NPK and 100% NPK + FYM during rabi 2017-18 and 100% NPK, 100% NP and 100% NPK + Zn during rabi 2018-19. Total N depletion by weeds in the maize – wheat cropping system ranged from 10.64 kg/ha/annum under the control treatment to 36.33 kg/ha under 100% NPK + FYM. P depletion varied from 2.77 kg/ha under the N only treatment to 10.08 kg/ha/annum under 100% NPK + FYM. Total K depletion due to weeds was minimum (9.14 kg/ha/annum) under the N only treatment and maximum (24.69 kg/ha/annum) under the 100% NPK + FYM. Maximum plant height, number of functional leaves/plant, number of plants, cobs/plant, cob weight, grain yield and stover yield and harvest index of maize were obtained in 100% NPK + FYM being statistically at par with 100% NPK + lime. Significantly taller plants, effective tillers, length of spike, number of grains per spike, 1000-grain weight, grain and straw yield of wheat were obtained under 100%NPK + FYM and 100% NPK + lime. Long-term application of 50% NPK sustained the maize and wheat grain yield equal to 100% NPK. There was significantly better maize and wheat grain yield due to imposition of hand weeding with the 100% NPK but the continue application of Zn along with the recommended dose of the fertilizer had no beneficial effect. During the 46th cropping cycle grain yield of 643 kg/ha in case of maize and 444 kg/ha of wheat was harvested under the control treatment but there was no yield under the 100% N only treatment. The importance of S, P and K for optimum production of maize-wheat cropping system was also realized from the results. In maize-wheat cropping system under various fertility treatments, net returns were highest for 100% NPK + FYM followed by 100% NPK + lime and highest B:C was highest for 100% NPK + FYM followed by 100% NPK + lime. However, there was a net loss of over 34 thousands under the, 100% NPK treatment and over 7 thousand under the control treatment. Also there was no net gain in the treatment where S was withdrawn.
Description
Keywords
null