• Influence of sowing date and tillage on growth, productivity of wheat and climate change assessment using simulation with CSM-CERS-Wheat model for the mid-western hills of Nepal

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  • 29/02/2016

This MSc thesis study was conducted by Srijana Marasini , student at the Tribhuwan University, as part of the SAF-BIN project in Nepal in 2014.

Wheat production in Nepal is constrained by rainfall variability and increasing drought periods, due the changing climate. Sowing time is a critical influencing factor to achieve optimal yield of the wheat varieties. Crop simulation models can assist in the determination of optimum sowing time, to improve the crop productivity. The aim of the study was to evaluate the Cropping System Model (CSM) -CERES-Wheat (ver. 4.5) for its ability to simulate growth, phenology, agronomic and climate change parameters of wheat cultivars under different establishment methods and sowing dates in the context of a Nepales rice production system. The study was conducted in the winter of 2014/2015 on farms in Kaski district, participating in the SAF-BIN project. A strip-split trial plot designs with 3 replications and sixteen treatments based on two tillage methods1, four wheat varieties and two sowing dates3 was used. Plant parameters were recorded and analysed using ANOVA and Duncan's Multiple Range Test. The CSM-CERES-Wheat model was calibrated for the local context and the best treatments. Genetic coefficients were adjusted towards a match between the observed and simulated parameters. Tillage, varieties and sowing date had significant effects on grain yield, straw yield, harvest index, leaf area index, dry matter accumulation and plant height. WK-1204 outperformed the other varieties in grain yield (3.11t/ha). Effective tillers/m2 and spike weight was influenced by tillage. The model is applicable and sensitive to weather years, applied N and temperature change, CO2 concentration and change of solar radiation. To achieve the highest wheat production variety WK-1204 variety should be sown using zero tillage around November 15. Farmers’ local variety, Annapurna-4 and Gautam profit from earlier sowing, but tillage method has no influence. The study revealed that the tested model can be safely used as a tool for sensitivity analysis under the local conditions.


1 tillage methods: (1) zero tillage (ZT): furrow made with a spade, 5t/ha straw mulch, (2) conventional tillage: 1 day before sowing; animal drawn plough, 2-3 times digging

2 Varieties: (1) farmer's local variety, (2) WK-1204, (3) Annapurna-4, (4) Gautam all sown at a rate of 120 kg/ha

3 Sowing dates. (1) November 15,   (2) November 30