An Aristida pungens-Retama r&m rangeland in the rrid Jefhra plain in Libya produced 2,000 and 950 kg (dry matter) ha-' of net above-ground phytomass with 200 mm and 171 mm of rainfall during the 1977178 and 78179 growing seasons, reavly. Annual plants contributed 460 and 300 kg (dry matter ha) in the 2 seasons, respectively. Perennial shrubs lost their 1978 winterspring aerial production during the long 1978 summer and dry winter when graxable forage was most needed. In contrast, spring production of annual plants remained available and graxable until late summer. Settlement of shepherds' families on site is not advised as the dead standing phytomass (270 kg dry wood ha-') may be rapidly exhausted for fuel consumption, leading to wind erosion problems on presently fixed sand dunes. Libya has embarked on a large rangeland development programme involving 2 million ha (Gintzburger and Bayoumi 1977) of its estimated 12.5 M ha of nonagricultural lands located above the 50 mm isohyet (Le Houerou 1965). Most rangeland development projects are located between the 100 and 200 mm year-' isohyets on what is considered as marginal, yet sometimes valuable, cropping land by local farmers. In the northwestern zones of Libya, approximately 500,000 ha were surveyed to provide Libyan authorities with vegetation maps as well as estimates of rangeland carrying capacities (GEFLI 1974) based upon research work in a similar environment in Tunisia (Le Houerou 1969, Floret et al. 1983). To provide their rural population with modern facilities, including schooling, medical care, and technical assistance in agriculture, the Libyan authorities have planned to allocate one set piece of rangeland to each shepherd's family. It was anticipated that each shepherd should derive an adequate minimum and sustained income from proper management of his land and flock of sheep and goats. Conflicting estimates of long-term carrying capacity (1.5 to 3 ha sheep-') reported by different advisory teams rendered rangeland management and planning difficult. Problems were compounded by desertification hazards in this region. Suggested long-term carrying capacities resulted largely from guesses or one-time measurement, usually at the supposed peak standing phytomass in a similar environment. The relationship between average annual rainfall and net consumable rangeland production proposed by Le Houerou and Hoste (1977) for the Mediterranean Basin, though useful, appeared to be optimistic and needing refinement. None of these estimates took into account the yearly distribution of the rangeland production or considered the contribution and availability of ephemerals (annuals and ephemeroids). This situation prompted the author to measure the seasonal variation of above-ground phytomass of a rangeland type representative of some lOO,OOO-200,000 ha of the Libyan Jeffara Plain. The information gathered was aimed at providing range managers with an improved knowledge of above-ground phytomass dynamics and forage availability throughout seasons, hence to assist in plan...
A series of experiments on communally-owned grasslands in the barley±livestock zone of north Syria were conducted to test the hypothesis that introduction of Mediterranean annual legumes will increase productivity. The experiments were preceded by a survey to determine farmers' attitudes, describe the farming systems and to select appropriate collaborators. The ®rst experiment examined the establishment of medics (Medicago spp.) and clovers (Trifolium spp.) distributed by hand, and monitored their eects on biomass and seedbank size. Later experiments extended these results to other villages. The principles of farmer participation in research were used to overcome the constraints imposed by the communal ownership of land.The survey revealed that the average size of the 20 villages was 36 families and that each village owned 887 sheep and 790 ha land. All villages had access to communally-owned grasslands, although their dependence on income from sheep varied greatly. These villages were subsequently divided into groups of high, intermediate and low potential.Of the 11 clovers sown in the ®rst experiment, seed numbers of T. tomentosum, T. purpureum, T. haussknechtii, T. pilulare and T. resupinatum increased over three years. By 1996, there were more than 3000 legume seeds m 72 in the seeded treatment compared with less than 2000 in the unseeded treatment (mainly the naturally-occurring Trigonella monspeliaca). The number of medic and clover seedlings also increased signi®cantly, while the number of Trigonella seedlings decreased signi®cantly. Biomass production increased in the ®nal two years and there was no response to added phosphorus.There were similar results in the later experiments. Seedbank size was greater in seeded treatments than in unseeded treatments, there were more seedlings in the seeded treatments, and the most successful species were T. campestre, T. tomentosum, T. speciosum and M. rigidula. The response in biomass was limited to the legume component, although total biomass increased in at least one of the two years. The highest biomass produced was 1112 kg ha 71 and there was no response to added phosphorus.The results suggested that the on-station research previously conducted at ICARDA headquarters was applicable to communally-owned land, although important modi®cations were needed. For example, at ICARDA phosphorus was necessary to stimulate the growth of legumes; in contrast, it was necessary to sow legumes at the four villages involved in these experiments. The results also suggested that the grasslands were common property, owned and controlled by de®ned groups of farmers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.