Annual Food Crops Research Articles

‘Systems research’ or ‘research with a systems perspective’ in Africa Some organizational and technical issues

Because of a lack of funds and of experienced scientific personnel, many of the African national agricultural research systems (NARS) tend to be poorly equipped to handle the complexities of a holistic systems research programme. Therefore, strengthening these NARS should start by reinforcing their thematic and commodity research programme, which necessarily involves the introduction of a systems perspective along with some on-farm activities. This approach would not require extensive institutional reorganization and would be far less costly than the creation of independent systems research units. Based on a detailed study of the Rwanda NARS in relation to agricultural development, it was concluded that both donors and NARS leaders should be more concerned about the integration of projects into the national institutional framework, starting from the design phase. Also the sustainability and continuity of the research activities in terms of operating cost and local manpower following project termination should be emphasised. As a result the overall national research programme would not become biased towards short-term production objectives such as for annual food crops; but would also address more complex and vital long-term issues, like land degradation and the sustainability of local and improved technologies, which would require integration between disciplinary activities of technical, biological and social scientists. To achieve these aims it is necessary that the scientists share a similar systems perspective which can be reinforced through participative methods that effectively link the research with the knowledge and needs of farmers and extension personnel.

Tree Crops and Farming Systems Development in the Humid Tropics

SUMMARYExamples are presented of tropical tree commodity plantation crops, tea, coffee, rubber and oil palm, as models for farm system development. They are environmentally benign in comparison with annual food crops, have been organized on a large scale with smallholder participation, and make significant contributions to local and national economies. It is suggested that lessons learned in their development might be used in the large-scale development of other potentially major tree crops, including timber, fruit and nut producing species.

Effect of water conservation on the yield of upland crops in the humid tropics

The high variability of the rainfall in the humiud tropics, with consequential excess or deficit of soil water determines the cropping patterns. It is also a major factor limiting the level of productivity of annual food crops. This paper presents some experiments in Malaysia aimed at a more intensive food crop production system not leading to increased erosion. The experiment investigated the effect of mulching on water use, water use efficiency and yield for various annual crops. Water balance experiments are described in which the internal drainage method was used to measure accurate values of unsaturated hydraulic conductivity to determine soil water fluxes. Average water consumption over the entire growing periods was found to be 3.01, 3.61, 2.96 and 4.05 mm/day for maize, mungbean, cowpea and chili respectively. The beneficial effect of mulching was proven in all the experiments. Rates of three tons/ha are recommended as they improve the yield of all crops tested and increase their water use efficiency by as much as 90%.

AGROFORESTRY AND THE SMALL FARMER: A CASE STUDY OF KILEMA AND KIRUA VUNJO IN KILIMAJARO

SUMMARY A system of agroforestry is described which involves the multiple cropping of coffee, bananas, timber fruit, fodder, ornamental and shade trees together with understorey annual and perennial food crops on the slopes of Mount Kilimanjaro. This system appears to be a relatively stable form of land use for small farms (average size 0.68 ha) in a highly populated area with a fragile environment.

Land Reserves in Southern Sumatra/Indonesia and their potentialities for agricultural utilization

In contrast to overpopulated Java the neighbouring island of Sumatra still provides huge unused land reserves. However, by far not all of these reserves can be regarded as real agricultural potentials, e.g. for resettlement projects. Especially the poor soils often prove an agricultural handicap. Besides soil fertility the existing vegetation has to be conidered. Thus, for example, the so called “alang alang grass savannas” in general show better potentialities than forest areas, while most of the swamps prove rather unsuitable for agricultural development. With regard to the already existing landuse types the cultivation of perennial bush- and tree crops, for instance rubber, seems to be best suited for further expansions. An expansion of annual food crops would be feasible too, however only be applying heavy capital inputs; here wet rice cultivation would be more appropiate than the permanent cultivation of annual upland crops like cassava, maize, etc. The traditional shifting cultivation does not serve as an alternative any longer. Animal breeding will have its difficulties, with the exception of certain highland areas. Taking into account all ecological, social, and economic reservations it is concluded that, in spite of considerable restrictions, a good part of the land reserves in southern Sumatra could still be opened and used successfully for agricultural purposes.

Yield Potential of Interplanted Annual Food Crops in Southeastern U. S.1

AbstractIntercropping may be one way to increase the productivity of land. If so, it is of scientific as well as practical interest to know how the increase is achieved and devise methodologies which will exploit such systems to the fullest. This report compares the productivity of two component intercrops with that of their respective monocultures under differing nitrogen regimes.Two soil conditions were tested in each of 2 years—a poorly drained Portsmouth fsl (Typic Umbraquult, fine‐loamy, mixed, thermic) and a well drained Orangeburg sl (Typic Paleudult, fine‐loamy, silicious, thermic). Treatment variables were cropping system (intercrops vs. monocultures), row arrangement, and N rates from zero to 270 kg/ha. Corn (Zea mays L.) was used as the overstory crop and soybeans (Glycine max L. Merr.), snapbeans (Phaseolus vulgaris L.), or sweet potatoes (Ipomea batatas Lam) as the interplanted understory species. All interplanted species were at the same population as their monoculture checks.With adequate N, monoculture corn in conventional rows (97 un) averaged 9,400 kg/ha. Planting monoculture corn in paired 46‐cm rows, with 147 cm between row pairs, caused a 12% reduction in yield. An additional reduction of 5 to 10% resulted when soybeans or snapbeans were interplanted into corn in the 147‐cm space between row pairs. Monoculture soybeans yielded 2,750 kg/ha with only minor variations among sites. Interplanted soybean yields were site and year dependent, however, and varied from 33 to 55% of their respective monocultures. Intercrop soybean yields were inversely related to the amount of N applied to corn. Yields of spring‐planted monoculture snapbeans ranged from 7,000 to 15,500 kg of fresh pods/ha. Regardless of yield level, however, interplanted snapbeans yielded 48% of the monoculture check. Fall snapbeans, relay interplanted into maturing corn in mid‐August, also produced about 50% of a crop. Land equivalent ratios (LER) of 1.20 to 1.40 thus suggest a 20 to 40% increase in total productivity during one 200‐day season by intercropping. Higher production by intercrops was most easily interpreted in terms of total leaf exposure. Monoculture corn had a leaf‐area duration (LAD) of 150 days; but when soybeans were interplanted into corn, LAD of the intercrop exceeded 300 days.

Deer Food Yields in Four Ozark Forest Types

The kind and amount of deer food varied between forest types and with rainfall in an Arkansas Ozark forest. The sparsely timbered cedar glades and bottomland hardwoods produced the most herb- age and evergreen browse. They received heaviest deer use when mast was scarce. The more densely stocked hardwood types grew less forage but were the main source of winter food in good mast years. Average mast yields were 5-10 times greater than average winter browse yields. This paper compares annual and seasonal deer food crops and their importance to deer maintenance in four forest types in the southeastern Ozarks. Data were col- lected within two stocked enclosures, one approximately 600 acres and the other 675 acres in size, on the Sylamore Experimental Forest in north Arkansas. Both enclosures included all four forest types in varying amounts, and the values in this report are for both tracts combined.