OPTIMIZATION OF THE PRODUCTION OF TWO VARIETIES OF SORGUM (Fadda and Soumalemba) AMENDED WITH COMPOST BASED ON Eichhornia crassipes LINKED TO Urtica dioica IN SAHEL AREAS NEAR LAKE CHAD

Sorghum production during the rainy season in the Lake Chad basin presents yield difficulties linked to soil degradation
linked to a difficult or catastrophic start to the season due to the late arrival of the rains. This often leads producers to
desperately use chemical soil fertilizer amendments which ultimately contribute to further impoverishing the soil with
inadequate yields. The objective is to elucidate the responses of two varieties of sorghum (Fadda and Soumalemba) to
nuanced additions of compost based on Eichhornia crassipes which could be oriented by meteorological information.
Late additions of compost based on Eichhornia crassipes can help boost the growth of plants. The method based on tests
on two experimental sites in split plot with six repetitions from 2021-2023 were conducted in Hilé Alifa on two sites (Site
1 and Site 2) on sandy soils in rainfed conditions. Two varieties (Fadda and Soumalemba) were subjected to six
fertilization methods: T0 = no fertilizer; T1 = 50 kg/ha of NPK (15-15-15) (50%) at emergence + 100 kg/ha of compost 0
(33.33%) at tillering + 150 Kg/ha of compost 1 (16.67 %) at the rise; T2 = 275 kg/ha of compost 1 (52.38%) at emergence
+ 125 kg/ha compost 2 (23.81%) at tillering + 125 Kg/ha compost 3 (23.81%) at emergence; T3 = 350 kg/ha of compost
1 (58.33%) + 125 kg/ha of compost 2 (20.83%) at bolting + 125 kg/ha of compost 3 (20.83%) at heading ; T4 = 475 kg/ha
of compost 1 (65.52%) + 125 kg/ha compost 2 (17.24%) at bolting + 125 Kg/ha of compost 3 (17.24%) at heading; T5 =
725 kg/ha of compost 1 (74.36%) + 125 kg/ha compost 2 (12.82%) at bolting + 125 Kg/ha of compost 3 (12.82%) at
heading. Late fertilization allowed stressed plants to resume their growth in the same way as if the additions were made
early in the season. Yields varied depending on the study site. The staggered intake of the recommended dose (T3) was
more beneficial than the T4 and T5 treatments. The two varieties showed different responses from each other, with the
Soumalemba variety responding better to late additions. The grain yield (1012.83± 303.18kg/ha on site 1 and
1018.75±296.01kg/ha on site 2) varied depending on the interactive effect of the environment (805.33± 158.35mm of
water received on site 1 and 822± 211.08mm of water received on site 2) and fertilization. Late additions of compost
varied depending on the site and the increase in grain yield due to the late application of compost fluctuated over the
years, depending on the meteorological parameters of the Sahelian localities.