בראשית שנות הששים הוקמה חות הנסיונות 'מגדה' בנגב הצפוני. ההחלטה להקים את החווה באה לאחר סדרה של שנות בצורת שחייבו תשלום פצויי בצורת גבוהים למגדלי הפלחה ועוררו את השאלה: האם יש חלופה לשיטת הפלחה השגורה?
החלופות שנבדקו התבססו על רעית צאן וכללו שלשה טפוסי מרעה: מרעה טבעי של צמחים חד-שנתיים שצמחו על שטחי הפלחה המוברים; מרעה זרוע תערבת של מיני מרעה חד-שנתיים, בעיקר קטניות חד-שנתיות (אספסת מצויה, אספסת קטועה (Barrel medic), תלתן ארגמן, בקיה ססגונית (Lana vetch), וזון אשון (Wimmera ryegrass); ומרעה שיחים, מלוח קיפח (Atriplex halimus) שתול בצפיפות של 160 צמחים לדונם ובשורות מרוחקות שלשה מטר אחת מן השניה.
שלבי הביצוע היו:
1961: הקמת החווה
1962- 1964: הקמת חלקות הניסוי, זריעת חלקות קטניות למרעה, שתילת חלקות מלוח קיפח, זריעת חיטה, גידור וסידורי מים.
1964- 1967: רעייה במשך כל חודשי השנה בשני שעורי איכלוס: 6 ו- 12 דונם לכבשה. בתום תקופה זו, התברר שאפשר להגדיל את שעור האכלוס
1967- 1972: ניסוי לחצי רעייה מ- 2 עד 10 דונם לכבשה על מרעה טבעי, מרעה זרוע קטניות ח"ש, ומלוח קיפח.
1971- 1974: מחקר לקביעת הייצור הראשוני הפוטנציאלי באזורים שחונים (בש"פ עם חוקרים מהאוניברסיטה החקלאית, וגנינגן, הולנד).
1974- 1977: חקר מחזור החנקן בקרקע בתנאים שחונים.
1977- 1981: חקר הייצור השניוני במערכות אינטנסיביות של מרעה זרוע בעל (בש"פ עם חוקרים מהאוניברסיטה החקלאית, והמרכז לחקר אגרו-ביולוגי - CABO, וגנינגן, הולנד).
1982- 1989: חקר השילוב של שיחי מרעה במערכות פלחה-מרעה באזורים שחונים (פרויקט משותף לארה"ב, מצרים, ישראל; במימון USAID ).
1983- 1988: פרויקט מגדה-כרמים, מבחן משקי של שיטת פלחה-מרעה שפותחה במגדה (במימון משרד החקלאות והסוכנות היהודית).
1987- 1989: חקר ערך מזוני של שיחי מרעה, פרויקט משותף עם קניה (במימון קרן גרמניה-ישראל, GIFRID ).
1990- 1998: חקר השילוב של רעייה בשיטת ממשק אי-פליחה בפלחה.
1999- 2003: מחזורים של גידולי מרעה זרוע בעל לגידול בקר.
Publications
All publications are in English unless otherwise stated
Articles in reviewed journals
Landau, S., Cabiddu, A., Molle, G., Fois, N., Friedman, S., Barkai, D., Decandia, M. Dvash, L. and Sitzia, M. (2005) Safflower (Carthamus tinctorius L.) as a novel pasture species for dairy sheep in the Mediterranean conditions of Sardinia and Israel. Small Ruminant Research 59: 239-249.
Landau, S., Decandia, M., Molle, G., Cabiddu, A., Scanu, G., Dvash, L. and Brosh, A. (2005) NIRS-aided evaluation of fecal output in goats browsing on Mediterranean woodland. Opt. Med., 67, 407-412.
Aharoni, Y., Brosh, A., Orlov, A., Shargal, E. and Gutman, M. (2004) Measurements of energy balance of grazing beef cows on Mediterranean pasture, the effects of stocking rate and season: 1. Digesta kinetics, faecal output and digestible. Livestock Production Science 90: 89-100.
Landau, S., Bonfil, D.J., Barkai, D., Yonatan, R., Mufradi, I., Dvash, L. and Brosh, A. (2004) A system analysis of the interaction between wheat crop management and sheep grazing in aftermath stubble. Options Med. 61)A(: 153-160.
Landau, S., Friedman, S., Brenner, S., Bruckental, I., Weinberg, Z.G., Ashbell, G., Hen, Y., Dvash, L. and Leshem, Y. (2004) The value of safflower (Carthamus tinctorius) hay and silage grown under Mediterranean conditions as forage for dairy cattle. Livestock Production Science 88: 263-271.
Barkai, D., Landau, S., Brosh, A., Baram, H. and Molle, G. (2002) Estimation of energy intake from heart rate and energy expenditure in sheep under confinement or grazing condition. Livestock Production Science 73: 237-246.
Zaady, E., Yonatan, R., Shachak, M. and A. Perevolotsky (2001) The effect of grazing on abiotic and biotic parameters in a semiarid ecosystem: a case study from the northern Negev desert, Israel. Arid Soil Research and Rehabilitation 15:245-261.
Landau, S., Silanikove, N., Nitsan, Z., Barkai, D., Baram, H., Provenza, F.D. and Perevolotsky, A. (2000) Short-term changes in eating patterns explain the effects of condensed tannins in heifers. Applied Animal Behaviour Science 69: 199-213.
Landau, Y., Silanikove, N., Nitsan, Z., Barkai, D., Baram, H. Provenza, F.D. and Perevolotsky, A. (2000) Short-term changes in eating patterns explain the effects of condensed tannins on feed intake in heifers Applied Animal Behaviour Science 69:199-213.
Degen, A. A., R. W. Benjamin and J. C. Hoorweg (2000) Bedouin households and sheep production in the Negev Desert, Israel. Nomadic Peoples 4:125-147.
Degen, A. A., R. W. Benjamin, T. Mishorr, M. Kam, K. Becker, H. P. S. Makkar and H. J. Schwartz (2000) Acacia saligna as a supplementary feed for grazing desert sheep and goats. Journal of Agricultural Science, Cambridge 135:77-84.
Benjamin, R. W., E. Oren, E. Katz and K. Becker (1992) The apparent digestibility of Atriplex barclayana and its effect on nitrogen metabolism in sheep. Animal Production 54:259-264.
Seligman, N.G., H. van Keulen and C.J.F. Spitters (1992) Weather, soil conditions and the interannual variability of herbage production and nutrient uptake on annual Mediterranean grasslands. Agricultural and Forest Meteorology 57: 2 65-279.
Seligman, N.G., R.W. Benjamin and I. Sepharim (1989) Multiple Goal Feasibility of Forage Shrub Plantations in a Semi-arid Mediterranean- Type Agropastoral System. Agricultural Systems 30: 335-350.
Arieli, A., Naim, E., Benjamin, R.W. and Pasternak, D. (1989) The effect of feeding saltbush and sodium chloride on energy metabolism in sheep. Animal Production 49: 451-457.
Seligman, N.G. and H. van Keulen (1989) Herbage production of a Mediterranean grassland in relation to soil depth, rainfall and nitrogen nutrition: a simulation study. Ecological Modelling 47: 303-311.
de Wit, C.T., H. van Keulen, N.G. Seligman and I. Spharim (1988) Application of interactive multiple-goal linear programming techniques for analysis and planning of regional agricultural development. Agricultural Systems 26: 211-230.
Degan A.A., R.W. Benjamin and E. Eyal (1987) A note on increasing lamb production of fat-tailed Awassi and German Mutton Merino sheep grazing in a semi-arid area. Animal Production 44: 169-172.
Seligman, N.G., Sala Feigenbaum, Dvora Feinerman and R.W. Benjamin (1986) Uptake of nitrogen from high C to N ratio 15N labelled organic residues by spring wheat grown under semiarid conditions. Soil Biology and Biochemistry 18: 303-307.
de Ridder N., R.W. Benjamin and H. van Keulen (1986) Forage selection and performance of sheep grazing dry annual range. Journal of Arid Environments 10: 39-51.
Seligman, N.G., Sala Feigenbaum, R.W. Benjamin and Dvora Feinerman (1985) Efficiency of fallow as a store for fertilizer nitrogen in a semiarid region. Journal of Agricultural Science (Cambridge) 105: 245-249.
Feigenbaum, Sala, N.G. Seligman and R.W. Benjamin (1984) Fate of 15N applied to spring wheat grown for three consecutive years. Journal of the Soil Science Society of America 48: 838-843.
Feigenbaum Sala, N.G. Seligman, R.W. Benjamin and Dvora Feinerman (1983) Recovery of tagged fertilizer nitrogen applied to rainfed spring wheat (Triticum aestivum L.) subjected to water stress. Plant and Soil 73: 265-274.
Spharim, I. and N.G. Seligman (1983) Identification and selection of technology for a specific agricultural region: A case study of sheep husbandry and dryland farming in the northern Negev of Israel. Agricultural Systems 10: 99-125.
Keulen, H. van, N.G. Seligman and R.W. Benyamin (1981) Simulation of water use and herbage growth in arid regions. A re-evaluation and further development of the model 'ARID CROP'. Agricultural Systems 6: 159-193.
de Ridder, N., N.G. Seligman and H. van Keulen (1981) Analysis of environmental and species effects on the magnitude of biomass investment in the reproductive effort of annual pasture plants. Oecologia (Berl.) 49: 253-271.
van Keulen H., N.G.Seligman and R.W.Benjamin (1981) Simulation of water use and herbage growth in arid regions- a reevaluation and further development of the model "ARID CROP". Agricultural Systems 6: 159-193.
Benjamin, R.W., M. Chen, N. G. Seligman, D. Wallach and M.J. al Hadad (1978) Primary production of grazed natural pasture and of grazed wheat in a semi-arid region of Israel. Agricultural Systems 3: 205-220.
Benjamin, R.W., M. Chen, N. Seligman, D. Wallach and M.J. al Hadad (1978) Primary production of grazed annual natural pasture and of grazed wheat in a semi-arid region in Israel. Agricultural Systems 3: 205-219.
Noy-Meir, I. and Harpaz, Y. (1977) Nitrogen cycling in semi-arid Agro-ecosystems in Israel. In: Cycling of mineral nutrients in agricultural ecosystems (ed. M.J. Frissel), Agro-ecosystems 4, 143-167.
Benjamin, R. W., A. A. Degen, A. Brieghet, M. Chen and N. H. Tadmor (1975) Estimation of food intake of sheep grazing green pasture when no free water is available. Journal of Agricultural Science, Cambridge 85:403.
Eyal E., Benjamin R.W. and Tadmor N.H. (1975) Sheep production on seeded legumes, planted shrubs and dryland grain in a semiarid region of Israel. Journal of Range Management 28: 100-107.
van Keulen, H., N.G. Seligman and J. Goudriaan (1975) Availability of anions in the growth medium to roots of an actively growing plant. Netherlands Journal of Agricultural Research 23:131-138.
Tadmor, N. H., A. Briechet, I. Noy-Meir, R. W. Benjamin and E. Eyal (1975) An evaluation of the calibrated weight-estimate method for measuring production in annual vegetation. Journal of Range Management. 28: 65-69.
Popular publications
Landau, S., Rosilio, I., Bonfil, D., Barkai, D. and Adiri, B. (2001) There is no contradiction between stubble grazing by sheep and no-till wheat management. Gan Sade VaMechek 3: 8-13 (Hebrew)
Leshem, Y., Katz, Y., Levi, A., Brikman, R., Landau, S., Devash, L. and Barkai, D. (2001) The effect of mechanical treatments on drying of safflower hay grown in the Negev Desert. Gan Sade VaMechek 6: 12-14 (Hebrew).
Landau, S. (2000) You say pasture, you see green. Pasture in the desert is different. Rosh Gadol 9: 26 (Hebrew)
Landau, S., Bonfil, D., Barkai, D. and Rosilio, I. (2000) No-till wheat farming and stubble grazing Hanoked 34:18-22 (Hebrew)
Seligman, N.G. and H. van Keulen (1987) Long term effects of agrotechnical practice and plant characteristics on grain yield of wheat (T. aestivum L.) growing in a Mediterranean semiarid region: an exercise in crop simulation. Israel Agresearch, 2: 37-52 (Hebrew, with English summary).
Seligman, N.G., I. Spharim, Dalia Harel, E. Eyal, R.W. Benjamin and Y. Benjamin (1983) Economic evaluation of agropastoral systems based on wheat and sheep husbandry applied to the northern Negev of Israel. 1. Effect of area of pasture in relation to the area of wheat. Hassadeh 63: 877-880 (Hebrew, with English summary).
Seligman, N.G., I. Spharim, E. Eyal, R.W. Benjamin, Dalia Harel and Y. Ofer (1983) Economic evaluation of agropastoral systems based on wheat and sheep husbandry applied to the northern Negev of Israel. 2. The effect of three-year legume pasture and of cheaper recycled feed on economic feasibility. Hassadeh 63: 1126-1128 (Hebrew, with English summary).
Benjamin, Y., J. Kali, D. Barkai, R.W. Benjamin and E. Eyal (1982) Feeding cattle manure for maintenance of mature ewes. Hassadeh, 63, 3: 565-569. (Hebrew, with English summary).
Benjamin, R.W., E. Eyal, I. Noy-Meir and N.G. Seligman (1982) Intensive agropastoral systems in the Migda Experiment Farm, northern Negev. Hassadeh 62: 2022-2025 (Hebrew, with English summary).
Benjamin, R., Eyal, E., Noy-Meir, I. and Seligman, N. (1977) The effect of sheep grazing on the grain yield and total dry matter production of wheat in an arid region. Hassadeh 57, 754-759 (Hebrew, with English summary).
Benjamin, R., Noy-Meir, I. and Seligman, N. (1977) Deferment of grazing in a natural pasture in a semi-arid region at the beginning of the grazing season. Hassadeh 57, 1868-1873 (Hebrew, with English summary).
Books and Book Chapters
Ungar, E.D. (1992) Management of agro-pastoral systems at the farm level. pp. 133-158 in: Th. Alberda, H. van Keulen, N.G. Seligman and C.T. de Wit (eds.): Food From Dry Lands - An Integrated Approach to Planning of Agricultural Development. Kluwer Academic Publishers, Dordrecht, The Netherlands. 211 pp.
van Keulen, H. and N.G. Seligman (1992) Moisture, nutrient availability and plant production in the semiarid region. pp. 25-81 in Th. Alberda, H. van Keulen, N.G. Seligman and C.T. de Wit (eds.): Food from Dry Lands - An Integrated Approach to Planning of Agricultural Development. Kluwer Academic Publishers, Dordrecht, The Netherlands. 211 pp.
Seligman, N.G. (1992) Description of a pasture system generator. pp. 101-132 in Th. Alberda, H. van Keulen, N.G. Seligman and C.T. de Wit (eds.): Food from Dry Lands - An Integrated Approach to Planning of Agricultural Development. Kluwer Academic Publishers, Dordrecht, The Netherlands. 211 pp.
Alberda, Th., H. van Keulen, N.G. Seligman and C.T. de Wit, editors (1992) Food from Dry Lands - An Integrated Approach to Planning of Agricultural Development. Kluwer Academic Publishers, Dordrecht, The Netherlands. 211 pp.
Noy-Meir, I. (1992) Structure and dynamics of grazing systems on seasonal pastures. pp. 7-24 in Th. Alberda, H. van Keulen, N.G. Seligman and C.T. de Wit (eds.): Food from Dry Lands - An Integrated Approach to Planning of Agricultural Development. Kluwer Academic Publishers, Dordrecht, The Netherlands. 211 pp.
Ungar, E.D. (1990) Management of agropastoral systems in a semiarid region. Simulation Monographs, PUDOC, Wageningen. 221 pages.
Noy-Meir, I. and N.G. Seligman (1979) Management of semi-arid ecosystems in Israel. pp. 113-160 in B. Walker (ed): Management of Arid Ecosystems. Elsevier Scientific Publishing Co., Amsterdam.
van Keulen H. (1975) Simulation of water use and herbage growth in arid regions. Simulation Monographs, PUDOC, Wageningen, The Netherlands. 176 pp.
Reports
Seligman, N.G., H. van Keulen, A. Yulzari, R. Yonathan, and R. Benjamin (1976) The effect of abundant nitrogen fertilizer application on the seasonal change in mineral concentration in annual mediterranean pasture species. Preliminary Report No. 754. Agricultural Research Organization, Bet Dagan, 12 pp.
כתב: דר' נעם זליגמן