Eragrostis tef (Zucc.) Trotter (tef) is a small annual grain, panicle-bearing, C₄ cereal crop native to Ethiopia, where it is a major staple food. The objectives of the present study were to characterize the responses of two tef genotypes to escalating nitrogen (N) levels in terms of shoot, root, and grain biomass production, N concentration and uptake, and to determine an optimum N range at which tef performance is maximized. The N was applied in the irrigation water (Fertigation) in order to provide a consistent concentration of N in the root zone. A second goal was to test the feasibility of growing tef in the hot, arid conditions of the Northern Negev Desert. Two experiments were carried out in the Gilat Research Station (Negev region, Israel), each testing two different genotypes of tef (405B and 406W), and each including five replicates for each treatment. In the winter of 2015–2016, tef plants were grown in perlite filled pots in a walk-in plastic-covered tunnel. Five different N treatments were applied through fertigation, meaning the fertilizer was applied with the irrigation water (10, 20, 40, 80, 120 mg L⁻¹). All other nutrients were applied at the same sufficient rate. In the summer of 2016, tef plots were sown in open-field and applied with four different rates of N fertilization (0, 30, 60, 120 mg L⁻¹). Biomass of the different plant parts, SPAD values, N, P and K concentration, and the lodging index were recorded in each experiment. The harvest index was also calculated. Optimum N fertigation concentration in both experiments was between 40 and 80 mg L⁻¹, under which the time to flowering was decreased, and yield and grain protein concentration were optimized. Underfertilization caused a decrease in overall plant growth, whereas overfertilization caused an increase in vegetative growth at the expense of grain yield. Potassium uptake increased along with increased N availability, whereas P uptake did not. The fertilization rate will always need to take into account local soil and climate conditions. The field experiment also pointed to low harvest index as a major limitation on tef cultivation in the Northern Negev.

中文翻译：

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半干旱地中海气候下Tef（Eragrostis tef）对氮肥的响应

Eragrostis tef（Zucc。）猪蹄（tef）是一年生小颗粒，圆锥花序，C ₄谷物作物原产于埃塞俄比亚，是主要的主食。本研究的目的是根据芽，根和谷物生物量的产生，氮的浓度和吸收量，表征两种特氟基因型对逐渐升高的氮含量的响应，并确定特氟表现的最佳氮范围被最大化。将氮施于灌溉水中（施肥），以在根部区域提供稳定的氮浓度。第二个目标是测试在北内盖夫沙漠炎热干旱的条件下生长特氟的可行性。在吉拉特研究站（以色列内盖夫地区）进行了两次实验，每个实验测试了两种不同的tef基因型（405B和406W），每个实验包括五次重复。在2015–2016年冬季，将特氟植物种植在步入式塑料覆盖隧道内的珍珠岩填充花盆中。通过施肥进行了五种不同的氮肥处理，这意味着将肥料与灌溉水一起施用（10、20、40、80、120 mg L^-1）。所有其他营养素均以相同的用量施用。在2016年夏季，在露天田地播种了特氟田，并以四种不同的氮肥施用量（0、30、60、120 mg L ^-1）施肥。在每个实验中记录不同植物部分的生物量，SPAD值，N，P和K浓度以及倒伏指数。还计算了收获指数。两个实验中的最佳氮肥浓度在40至80 mg L ^-1之间，减少了开花时间，并优化了产量和籽粒蛋白质浓度。施肥不足导致整体植物生长下降，而施肥过度导致营养生长增加，但以谷物产量为代价。钾的吸收随着氮的有效性的增加而增加，而磷的吸收却没有。施肥率将始终需要考虑当地的土壤和气候条件。田间试验还指出，低收成指数是北部内盖夫地区特氟烃种植的主要限制。