The study was set to assess a complementary irrigation effect on seed cotton yields in the Northern Côte d’Ivoire where the cotton is the main cash crop. Firstly, the soil samples were collected from the surface down to 30 cm depth and analyzed. The soil was sandy and silty. So, 65 kg of 46%urea and 285 kg of NPKSB15-15-15-6-1 were applied for its correction. Secondly, in a complete randomized blocks, four tests were conducted, within those were T0 (no complementary irrigation and no crop protection products and fertilizers), T1 (no complementary irrigation, with crop protection products and fertilizers, the cotton cultivation ongoing practice in the Northern Cote d’Ivoire, therefore the reference), T2 (complementary irrigation, along with crop protection products and fertilizers), T3 (only complementary irrigation, without any crop protection products and fertilizers). Thirdly, the tests were replicated in 3 blocks. As a result, from T1 to T2, the plants heights, the plants density at harvest period, bolls number per plant and seed cotton yields were respectively 88.58±1.78 vs 96.08±1.78 cm (+8.47%) at day 73; 53,934±1,260.78 vs 67,593±1,260.78 plants per ha (+25.32%); 23.11±0.81 vs 26.39±0.81 bolls per plant (+14.19%) and 1,616.26±67.86 vs 2,657.77±67.86 kg/ha (+64.44%). Conversely, the complementary irrigation led to higher pest damages on bolls, because 13±2.2% of T2 bolls were attacked, while just 4.6±2.2% of T1 bolls were damaged by insects’ pest. Looking for solutions linked to climate change effects, a complementary irrigation in cotton farms in the Northern Côte d’Ivoire could be profitable to the cotton growers. Nonetheless, the farmers should pay a great attention to the pest management.

Methane (CH 4 ) emissions from Chinese paddy soil (Zhejiang province) were measured over the rice growing seasons. Different fertilizers (organic and chemical) were applied, emissions of methane were high during two periods (05 days after peak tillering and 07 days after heading flowering stage) and significant effects of fertilizers were observed. Methanogenic activities in soils treated with organic manure were obviously higher than those with chemical fertilizers. Among the organic manure fields the maximum methane emission from green manure, biogas residue and beef manure treatment were 52, 20 and 19 times, respectively of that given by control, and among chemical fertilizers it was NH 4 HCO 3 > CO(NH 2 ) 2 > (NH 4 ) 2 SO 4 > NH 4 Cl >NaNO 3 with 2.4, 2, 1.5, 1.3, and 0.2 times, respectively of that from control.

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