Field evaluation of maize-legume intercropping systems in the mid-hills of Nepal Name student(s): Hsiang-En Wei Date: 9/5/2016 Farming Systems Ecology Group Droevendaalsesteeg 1 – 6708 PB Wageningen - The Netherlands Field evaluation of maize-legume intercropping system in the mid-hills of Nepal Name student(s): Hsiang-En Wei Registration number student: 900511936090 Credits: 36 ECTs Code number: FSE-80436 Name course: MSc Thesis Farming Systems Ecology Supervisor(s): Maria Victoria Alomia Hinojosa, Jeroen Groot Professor/Examiner: Egbert Lantinga i Preface This study is part of master of plant science and under the supervision of farming system ecology group in Wageningen University. It is the second year research following the master’s thesis of Arun Thapa in 2014. A field experiment was designed and conducted in the mid-hills of Nepal in order to improve the maize-based cropping system which was the majority in local. Hope the results can be useful to the agricultural development associations and scientific communities who would like to make progress for the agricultural production in Nepal. It is my first time to conduct an experiment and present it with report on academic scale. Since the development of proposal and literature research, I faced plenty of difficulties especially in writing introduction and defining research questions. Thanks to the suggestions and work of Arun, his study highly inspired me and saved my time. The life in Nepal was another adventure and challenging, because I had to schedule the weekly measurement together with adjusting my living habit. Without any transportation means and Nepalese speaking, I really thanks to the great help of Mr. Resham K.C. who is the researcher of CIMMYT-CISA (Nepal). He tried his best to support me not only by weekly riding me to the fields and recording, but by sincerely taking care of my living in Dadeldhura. Besides, this gratitude was given to the Gyanu, family of Niraj, Prakash and Sudip Shahi who helped me whenever it was needed. I also thanks to Maria Victoria Alomia Hinojosa who is the Ph.D. candidate of Farming System Ecology group and my supervisor. I went back to Taiwan earlier than schedule when it was closing to the harvest due to the serious ill of my father. It was Victoria who execute harvest and collected the rest of data until November. After coming back to the Netherlands, I started to focus on data analysis. Thanks to dr. ir. Jeroen Groot of the Farming System Ecology group who is also my supervisor, his inspiring ideas allowed me to interpret my results better. In the last month of thesis finalization, the comments from Dr. Jeroen and Victoria largely complimented the deficiency and strengthened the work entirely. Lastly, I am sincerely grateful to my family and girlfriend. Their economic support and accompany are the most important things for me to succeed in finishing the thesis. This process taught me not only the academic training, but also the importance of interaction and cooperation with surroundings. Hsiang-En Wei ii Abstract An intercropping experiment between maize-legumes was conducted in Dadeldhura, Nepal from June to November in 2014 and 2015. The objective of this study was to evaluate the maize-legumes intercropping system as an improvement of maize-based cropping system in the mid-hills of Nepal. Treatments in the study were determined by three different crops and mono-/intercropping and were compared to the farmer’s practice (FP). These included sole maize (SM), sole soybean (SS), sole cowpea (SC), maize-soybean 1:1 alternative row intercropping (M+S) and maize-cowpea 1:1 alternative row intercropping (M+C). The grain yield of maize was not influenced by the cropping system for both years, which was also indicated by the growth parameters (plant height, active leaf number, leaf length, and leaf width). Maize biomass had a better growth in 2014, and its yield was lower in the intercropping treatments for both years. The grain yield of soybean performed better in 2015 but the stover yield was better in 2014. Soybean intercropped with maize had a lower grain and stover yield in both years. Cowpea had higher fresh pod yield in 2014, and the stover yield of cowpea was unaffected by neither years nor treatments effects. Land equivalent ratio (LER) indicated the yield advantage of maize-legumes intercropping systems. The LER of M+S and M+C in 2014 and 2015 were 1.54, 1.68, 1.35, and 1.32 respectively. The intercropping systems showed weed control starting at 81 days after sowing (DAS) and it was confirmed by weed smothering efficiency (WSE). Ageratum conyzoides was the dominant species of weed in 2015. In 2015 the light interception of M+S and M+C attained 97.9 and 92.1 % at 69 DAS. By calculation of gross margin in 2015, M+S got the highest economic return of 120511 NRs ha-1 and was followed by SM (81818 NRs ha-1) and SS (73249 NRs ha-1). The intercropped with legumes for maize brings about the increased income. Additionally, the intercropping systems are better on weed suppression than the sole cropping. In sum, we recommend to use line sowing for maize-legume intercropping with fertilizer application. These alternatives can offer the Dadeldhura farmers the higher yield with better economical return, while decrease the labor demand. Keywords: intercropping, maize, legumes, Nepal, yield, HI, LER, light interception, weed control, margin gross iii List of abbreviation BNF Biological Nitrogen Fixation GDP Gross Domestic Product CBS Central Bureau of Statistics DAP Di-Ammonium Phosphate DAS Days After Sowing FWE Fresh Weight of Ear FWG Fresh Weight of Grain FYM Farmyard Manure HI Harvest Index LA Leaf Area LAI Leaf Area Index LER Land Equivalent Ratio MC Moisture Content MOP Muriate of Potash NRs Nepalese Rupees PAR Photosynthetically Active Radiation PLER Partial Land Equivalent Ratio SP Shelling Percentage TLER Total Land Equivalent Ratio WSE Weed Smothering Efficiency iv List of tables Table 1. Participating farmers at on-farm trial on two experimental sites. .................. 12 Table 2. Description for the five treatments and farmers’ practice. ............................. 13 Table 3. Grain yield for the three crops within different cropping systems in 2014/2015. ................................................................................................... 22 Table 4. Grain yield per plant for the three crops within different cropping systems in 2014/2015. ................................................................................................... 23 Table 5. Stover yield for the three crops under different cropping systems in 2014/2015. ................................................................................................... 23 Table 6. Stover yield per plant for the three crops within different cropping systems in 2014/2015. ................................................................................................... 24 Table 7. Harvest index for three crops under different cropping systems in 2014/2015. ...................................................................................................................... 24 Table 8. Land equivalent ratio within different cropping systems in 2014/2015. ....... 25 Table 9. Total weed biomass, total weed density, and weed smothering efficiency (WSE) at 54 and 81 days after sowing within different cropping systems in 2015.............................................................................................................. 25 Table 10. Percentage based on number for each weed variety within different cropping systems in 2015. ........................................................................................... 26 Table 11. Leaf area per plant and leaf area index for three crops within different cropping systems in 2015............................................................................. 26 Table 12. Economic analysis for different cropping systems in 2015. ........................ 28 v List of figures Figure 1. Monthly rainfall and average air temperature during growing season 2014 and 2015 (Weather Underground). ............................................................... 11 Figure 2. Planting pattern for different cropping system. ............................................ 14 Figure 3. Growth stage of maize (Illinois agronomy handbook). Vegetative stages: emergence stage (VE), nth leaf stage (Vn) and tasseling stage (VT). Reproductive stages: silking (R1) and maturity (R6). ................................. 16 Figure 4. Changes in morphological characteristics of maize within different cropping systems during the growing season in 2015 (SM=sole maize; M+S=maize and soybean; M+C=maize and cowpea; FP=farmers’ practice). ................. 21 Figure 5. Changes in PAR interception for three crops within different cropping systems during growing season in 2015. ..................................................... 26 Figure 6. The leaf area index of different cropping systems in 2015 (SM=sole maize; SS=sole soybean; SC=sole cowpea; M+S=maize and soybean; M+C=maize and cowpea). Different characters means significant difference at P<0.05 by using LSD. ................................................................................................... 27 vi Table of content Abstract ........................................................................................................................ iii List of abbreviation ....................................................................................................... iv