Mulching and Fertilization Effects on Weed Dynamics under Conservation Agriculture-Based Maize Cropping in Zimbabwe †

Environments

Florence Mtambanengwe¹  Hatirarami Nezomba¹  Tonny Tauro²  Christopher Chagumaira¹  Muneta G. Manzeke¹  Paul Mapfumo¹  Amir Kassam³  Saidi Mkomwa³ 

[1] The Soil Fertility Consortium for Southern Africa (SOFECSA), Department of Soil Science & Agricultural Engineering, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare 00263, Zimbabwe; E-Mails:;Marondera College of Agricultural Science & Technology, c/o University of Zimbabwe, P.O. Box MP 167, Mt Pleasant, Harare 00263, Zimbabwe; E-Mail:The Soil Fertility Consortium for Southern Africa (SOFECSA), Department of Soil Science & Agricultural Engineering, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare 00263, Zimbabwe;

关键词: basins;    conventional tillage;    ripping;    Shannon Weiner index;    soil fertility;    weed density;    weed diversity;   

DOI  :  10.3390/environments2030399

来源: mdpi

【 摘 要 】

A two-year study was conducted to assess how mulch influences weed dynamics following imposition of different fertilization treatments under three crop establishment options: (i) conventional; (ii) ripping; and (iii) basin, in a two-year maize-legume rotation. Eight treatments were imposed within each crop establishment option and received maize stover mulch applied at 0% or 30% cover before planting  maize (Zea mays) or cowpea (Vigna unguiculata) as test crops. Maize received nitrogen (N) at 35, 90, or 120 kg·ha⁻¹ and phosphorus (P) at 14 or 26 kg·ha⁻¹ applied alone or in combination with 4 or 7 t cattle manure·ha⁻¹, while cowpea received 8 or 17 N·kg·ha⁻¹ and similar P rates to maize. Results indicated that both weed biomass and diversity were influenced more by fertilization than method of crop establishment. On treatments under high fertilizer application rates, or previously planted to cowpea weed biomass ranged between 220 and 400 g·m⁻² under mulch and 370–510 g·m⁻² (no mulch). Here species richness ranged between 7–16 and was dominated by dicotyledons. This was in contrast to biomass ranges of 75–200 g·m⁻² in the low fertilized and control plots, where only one or two grass types dominated. Overall, weed densities were 6% to 51% higher under conventional tillage compared to the two conservation agriculture (CA) options, although the data indicated that mulch significantly (p < 0.05) depressed weed density by up to 70%. We concluded that mulching could be a potential mechanism for reducing weeding labor costs for smallholders and the general environmental and health concerns associated with the use of herbicides in CA systems.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.