Yields and Quality of Italian Ryegrass (Lolium multiflorum) and Common Vetch (Vicia sativa) Grown in Monocultures and Mixed Cultures under Irrigated Conditions in the Highlands of Madagascar

Volatsara B Rahetlah,Lucile H Razafimpamoa,Blandine Andrianarisoa,Jean M Randrianaivoarivony,Vololoniaina L Ramalanjaona

doi:10.5539/sar.v2n1p15

Abstract

<p>A field experiment was conducted under irrigated conditions in the highlands of Madagascar to assess the potential of intercropping Italian ryegrass with common vetch for improving yield and quality of forage. Seed proportions studied were ryegrass-vetch 100:0; 0:100; 50:33; 50:50; 50:66; 75:33 and 75:66. Mixtures were sown in alternate rows and the sowing rates of pure stands of ryegrass and vetch were 20 and 60 kg per hectare, respectively. The results showed that all mixtures achieved yield advantage over pure stands with the highest land equivalent ratio value for dry matter yield obtained from the mixture of 75:66 (1.47) followed by 50:50 (1.35). Slight increase of crude protein content and protein digested in the small intestine when rumen-fermentable nitrogen is limiting (PDIN) content were obtained from mixtures compared with pure stand of ryegrass. Vetch rate in dry matter yield of mixtures increased with the increase of vetch seed proportion and ranged from 31 to 44%. Agressivity and competitive ratio indices showed that ryegrass was slightly competitive than vetch. Intercropping Italian ryegrass with common vetch at the seed proportions of 75:66 or 50:50 could be a more sustainable alternative cropping to alleviate dry season feed shortages of dairy livestock in the highlands of Madagascar.</p>

Highlights

Dairy farming is an important source of incomes for mixed crop-livestock smallholder farmers in the central highlands of Madagascar (Raharimalala, 2002)
A field experiment was conducted under irrigated conditions in the highlands of Madagascar to assess the potential of intercropping Italian ryegrass with common vetch for improving yield and quality of forage
The results showed that all mixtures achieved yield advantage over pure stands with the highest land equivalent ratio value for dry matter yield obtained from the mixture of 75:66 (1.47) followed by 50:50 (1.35)

Summary

Introduction

Dairy farming is an important source of incomes for mixed crop-livestock smallholder farmers in the central highlands of Madagascar (Raharimalala, 2002). One of the main limiting factors for increasing production and productivity of dairy livestock is feed shortage in both quality and quantity especially during the dry and cool season. During the five to six months dry and cool season, significant decrease of milk yield is mainly attributed to the lower quality of the diet primarily composed of crop residues especially rice straw. Italian ryegrass (Lolium multiflorum L.) is a widely grown off-season forage crops in the highlands of Madagascar. It is cultivated under irrigated conditions www.ccsenet.org/sar

Methods

Results

Discussion

Conclusion